Coder Legion - Recent posts tagged string

Write a java program to count the letters, spaces, numbers and other characters of an input string.

Thu, 03 Sep 2026 12:40:15 +0000

First take the input form the user as a string
copy that string into a character array
write logic for checking each character of character array is a letter/number/space/other-character
print all the updated values of variables

Note :- There is pre-built fuctions to copy all characters of string into a character array which is :
char name_of_character_array[ ] = name_of_string.toCharArray and There are also pre-bilut functions are there to check weather character is letter/number/space in an array which are : Character.isLetter(ch[i]) , Character.isDigit(ch[i]) , Character.isSpaceChar(ch[i]) respectively

Unity Devs: Stop Starving Your Frame Rate!

Sat, 13 Jun 2026 11:48:39 +0000

Unity Devs: Stop Starving Your Frame Rate! Embrace Modern Memory Discipline

It’s 2026, and I’m still seeing incredible Unity games marred by avoidable Garbage Collection (GC) spikes, inexplicably dragging frame rates down from silky smooth to stuttering messes. We’ve got powerful tools like Burst, DOTS, and advanced asynchronous patterns at our fingertips, yet many developers are missing the fundamental lesson: memory discipline. Every string concatenation, every List<T> resize without pre-allocation, every casual LINQ query hurts. These small, seemingly innocuous actions accumulate into significant performance bottlenecks as your game scales.

The good news is that modern C# offers powerful, accessible solutions. Span<T>, Memory<T>, and ArrayPool<T> aren’t just for optimization gurus anymore; they’re mandatory for any serious C# game developer aiming for consistent, high frame rates. It’s time to embrace a data-oriented mindset, even within your MonoBehaviour scripts, and stop treating memory as infinite. Your players (and their frame counters) will thank you.

Code Layout & Walkthrough: Taming Allocations

The core problem is the managed heap. When you new up an object or perform an operation that implicitly allocates memory, that memory needs to be tracked. Eventually, the Garbage Collector (GC) steps in to reclaim unused memory. This process, however, is not free; it causes CPU overhead and can pause your game thread, leading to those dreaded frame spikes. Our goal is to minimize these allocations, especially during hot code paths.

1. String Operations: Beyond Basic Concatenation

Strings are often the silent killers of frame rates because they are immutable. Every time you “modify” a string (e.g., concatenation with +), you’re actually creating an entirely new string in memory.

The Problematic Way:

void LogPlayerScore(int playerId, int score) {
    // Each '+' operator creates a new string intermediate
    string log = "Player " + playerId + " scored " + score + " points!"; 
    Debug.Log(log); 
}

The Optimized Way (using StringBuilder):

StringBuilder allows you to construct strings piece by piece without creating intermediate string objects for each part.

using System.Text;

// Use a static/reusable StringBuilder to avoid allocating it repeatedly
private static readonly StringBuilder s_stringBuilder = new StringBuilder();

void LogPlayerScoreOptimized(int playerId, int score) {
    s_stringBuilder.Clear(); // Clear for reuse
    s_stringBuilder.Append("Player ")
                   .Append(playerId)
                   .Append(" scored ")
                   .Append(score)
                   .Append(" points!");
    Debug.Log(s_stringBuilder.ToString()); // One allocation for the final string
}

For advanced scenarios involving parsing or formatting into fixed-size character buffers, Span<char> offers direct, allocation-free memory access.

2. Dynamic Collections & Array Pooling

List<T> is convenient, but frequent new List<T>() calls or implicit resizing (when Capacity is exceeded) are major allocation points. For temporary buffers, ArrayPool<T> is your best friend.

The Problematic Way:

List<Vector3> GetNearbyPositions(Vector3 center, float radius) {
    List<Vector3> positions = new List<Vector3>(); // Allocation
    // ... logic to populate 'positions' ...
    return positions; // Potentially triggers resize allocations during population
}

The Optimized Way (using ArrayPool<T> and Span<T>):

ArrayPool<T> provides a pool of reusable arrays, drastically reducing allocations for temporary collections. Span<T> then gives you a high-performance, allocation-free “view” into that raw array memory.

using System.Buffers;
using UnityEngine; // For Vector3

void ProcessTemporaryVectorData(int count) {
    // Rent a buffer from the shared pool. Avoids allocation if available.
    // 'count' should be the maximum expected size.
    Vector3[] buffer = ArrayPool<Vector3>.Shared.Rent(count); 
    
    // Create a Span<Vector3> as a view over the rented buffer
    Span<Vector3> data = buffer.AsSpan(0, count); 

    // Use 'data' (Span<Vector3>) here; operations are allocation-free
    for (int i = 0; i < data.Length; i++) {
        data[i] = new Vector3(Mathf.Sin(i), Mathf.Cos(i), 0);
    }
    Debug.Log($"Processed {data.Length} vectors. First: {data[0]}");

    // IMPORTANT: Return the buffer to the pool when you're done.
    ArrayPool<Vector3>.Shared.Return(buffer); 
}

The Span<T> allows direct manipulation of the array’s elements without any intermediate copies or allocations.

3. LINQ’s Hidden Costs

LINQ (Language Integrated Query) is expressive, but many extension methods (Where, Select, OrderBy, etc.) implicitly create enumerator objects or even new collections behind the scenes, leading to GC pressure.

The Problematic Way:

using System.Collections.Generic;
using System.Linq; // Requires System.Linq namespace

IEnumerable<GameObject> GetActiveEnemies(List<GameObject> allObjects) {
    // Creates an enumerator object for Where, potentially for ToList()
    return allObjects.Where(obj => obj != null && obj.activeSelf && obj.CompareTag("Enemy"))
                     .ToList(); // Explicitly allocates a new List
}

The Optimized Way (Manual Iteration & Reusable Collections):

For performance-critical code, a good old-fashioned loop is often superior. Even better, pass in a pre-allocated List<T> to store results, effectively eliminating repeat allocations.

using System.Collections.Generic;
using UnityEngine;

// Pass in a 'results' list to be cleared and reused
void GetActiveEnemiesNoAlloc(List<GameObject> allObjects, List<GameObject> results) {
    results.Clear(); // Clear the existing list for reuse

    foreach (var obj in allObjects) {
        if (obj != null && obj.activeSelf && obj.CompareTag("Enemy")) {
            results.Add(obj); // Add to the reusable list
        }
    }
}

Here, results is only allocated once (or whenever its capacity needs expansion), avoiding new List<GameObject>() every frame or every call.

Conclusion

GC spikes are not an inevitable evil; they are often a symptom of insufficient memory discipline. By consciously adopting tools like StringBuilder for string manipulation, leveraging ArrayPool<T> for temporary buffers, and embracing Span<T> and Memory<T> for high-performance memory access, you can drastically reduce your game’s allocation footprint. Combine this with the practice of reusing collections instead of constantly instantiating new ones, and you’ll see tangible improvements.

Embrace this data-oriented mindset. Understand where your memory is going. Stop treating memory as infinite. Your players will experience smoother, more consistent frame rates, and your game will feel significantly more polished. Start integrating these practices into your Unity projects today.

Convert the string into Camel case and remove special characters from string in C, C++

Mon, 25 May 2026 04:00:43 +0000

You might have encountered situation that's required to Convert the string into Camel case and remove special characters from string in C or C++. To solve this problem, we can simply converting the string to camel case, then eliminating all special characters. In this article, we will also go over details with examples.

Identify the problem
Solution
1. Solution in C++
2. Solution in C
Conclusion
Reference

1. Identify the problem#

An usual string, such as this sentence "Hello World! How are you today?", is not only contain word seperated by space. It's also has some special characters like the question mark '?' or the exclamation mark '!'. We only need the words and digits to remain, and erase the rest.

Input

How old are you? I'm 15 years old

Output

HowOldAreYouIm15YearsOld

2. Solution #

Take the first example:

Hello World! How are you today?

It'll be easier to consider this problem as 2 smaller sub-problem: Converting a string to camel case, and removing all special characters from a string. We will go into the details of the solution with both C and C++, as well as things to keep in mind for each method.

1. Solution in C++

We first create a function 'toCamelCase(string str)' which takes a string as an input and converts it to camel case.


void to_camel_case(std::string &s) {
  if (s.empty()) return;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] == ' ' || s[i] == '_') {
      int j = i + 1;
      if (j < s.length()) {
        s[j] = toupper(s[j]);
      }
    }
  }
}

Then, we design a function called 'removeSpecialChars(string str)' to return the input string after removing all special characters.


void remove_special_characters(std::string &s) {
  if (s.empty()) return;
  for (int i = 0; i < s.length(); i++) {
    if (!isalnum(s[i])) {
      s.erase(i, 1);
      i--;
    }
  }
}

2. Solution in C

There seemes no obvious different when comparing to the solution in C++. First we convert string to camel case, then remove special characters.


void to_camel_case(char *s) {
  if (s == NULL) return;
  int len = strlen(s);
  if (len == 0) return;
  for (int i = 0; i < len; i++) {
    if (s[i] == ' ' || s[i] == '_') {
      int j = i + 1;
      if (j < len) {
        s[j] = toupper(s[j]);
      }
    }
  }
}


void remove_special_characters(char *s) {
  if (s == NULL) return;
  int len = strlen(s);
  if (len == 0) return;
  for (int i = 0; i < len; i++) {
    if (!isalnum(s[i])) {
      for (int j = i; j < len; j++) {
        s[j] = s[j + 1];
      }
      len--;
      i--;
    }
  }
}

But we need to pay attention to the type of string in C.

Caution In C++, we use the std::string class to handle strings, which provides a lot of helpful methods for manipulating strings, such as erase and empty. In C, we have to use arrays of characters, and manually manage memory allocation and deallocation.

The C++ implementation provides a more convenient and easier-to-use interface for string manipulation, while the C implementation provides a lower-level interface that gives you more control over memory and performance.

Finally, after execute 2 functions, we will be able to receive the desired result

Output

HelloWorldHowAreYouToday

3. Conclusion#

Going through this article, we've discussed about how to Convert the string into Camel case and remove special characters from string in C and C++ , by raising the first letters from each word to uppercase first, after that removing the special characters. I recommend reading in details to understand better how it works and knows the different between 2 cases. Have a nice day!

4. Reference#

For further information, please visit:

toupper(): cplusplus.com/reference/cctype/toupper
string: https://devdocs.io/c/string/byte

All about the function which is used to parse a string to int

Sun, 10 May 2026 10:37:33 +0000

There are so many programming languages in the world that are being used to create different applications. All of those programming languages, at some point, need to take data as input from the user and perform operations on user data. Some information is numeric while the other is alphabetic and some contain a combination of alphabets, numbers, and symbols. But everything entered by a user is in String format by default. So, in every programming language, there is a function that is used to convert that string to numbers. In this article, we are going to see the functions used to parse a string to integer in 5 different programming languages i.e. C, C++, Java, C#, and Python.

Parsing String to int in C:

To parse a string to int, we use the atoi() function. atoi() is the abbreviation of ASCII to Integer. The syntax for using this method is as follows:

atoi(string);

This method returns the integer representation of the string. If the string is not numeric, it returns 0. Here is an example program that demonstrates the use of the atoi() function:

#include 
#include
#include

int main()
{
    int number = atoi("6");    //Converting 6 from string to integer
    printf("%d",number);   //printing the result
    return 0;
}

Output:

Parsing String to int in C++:

As you might already know that C++ is the advanced version of C, there is not a lot of difference in the functions used in C and C++. In C++, we have stoi() function. stoi is the abbreviated form of String to Integer. The syntax for using this function is as follows:

stoi(string);

This function returns the integer representation of the string passed to it. If the string is not numeric, it returns 0. Here is an example program:

#include 
#include
using namespace std;

int main()
{
    int number = stoi("6");    //Converting 6 from string to integer
    cout

Output:

Parsing String to Int in Java:

Java is an easy-to-learn programming language that provides so many easy ways to perform complex tasks. There is an Integer class that contains a method named parseInt() that can be used to convert a string to an integer. Just like the rest functions in the rest of the programming languages, the parseInt() returns the numeric representation of the string. The syntax for using this method is as follows:

public class Main
{
public static void main(String[] args) {
    String str = "1234";
int number = Integer.parseInt(str);
System.out.println(number);
}
}

Output:

Parse String to Integer in C#:

In C#, we have two ways to convert a string to an integer:

Using the ToInt() method of the Convert class.
Using int.Parse() method

Let’s see both one by one:

Convert.ToInt():

This method is used according to the following syntax:

Convert.ToInt(string);

This method also returns the numeric representation of the string passed to it.

Example:

using System;
class HelloWorld {
  static void Main() {
    string str = "1234";
    int number = Convert.ToInt32(str);
    Console.WriteLine(number);
  }
}

Output:

Int32.Parse():

The syntax for using this method is as follows:

int32.Parse(string);

Example:

using System;
class HelloWorld {
  static void Main() {
    string str = "1234";
    int number = Int32.Parse(str);
    Console.WriteLine(number);
  }
}

Output:

Both of these methods throw an exception when the string passed to them is not numeric.

Parse String to Int in Python:

Python is the simplest yet complex language of all but converting a string to an integer is easiest in Python. You can do so by following the following syntax:

int(string)

Example:

print(int("1234"))

Output:

If the string passed to this function is non-numeric, the Python gives an error.

I hope you find this article helpful!

TypeError: unsupported operand type(s) for +: 'int' and 'str' in Python

Thu, 09 Apr 2026 23:33:33 +0000

The exception or error message TypeError: unsupported operand type(s) for +: 'int' and 'str' appears because an integer and a string operands are operated by the + or addition operator. The operands are the objects of type int and str. This error is usually encountered by people new to Python. This post will discuss this mistake and how to avoid it.

What is the problem?
How to avoid this error?
Conclusion
References

1. What is the problem? #

Let us dissect the exception message TypeError: unsupported operand type(s) for +: 'int' and 'str'.

TypeError - It is an exception class that tells us there is an error in the code related to the type of the object and the operator used on the object.
unsupported operand - The operand or items being operated. For example in 2 + 5, the 2 and 5 are called operands and the + is called the operator.
type(s) - The type() is a built-in function used to get the type or class of an object.
+ - The operator that performs addition if the operands are numeric like int 50 or float 25.5, or concatenation if operands are str.
'int' and 'str' - The type of operands, one is of type int and the other is of type str.

Let us look at some examples of how to get and check the type of an object.

How to get the type of an object?
Use the type() built-in function.

var_1 = 100
var_1_type = type(var_1)
print(var_1_type)

output

<class 'int'>

How to check if an object is an int or integer?
Use the insinstance() built-in function.

var_2 = 50
if isinstance(var_2, int):
    print(f'var_2 is of type int')

output

var_2 is of type int

How to check if an object is an str or string?
Use the isinstance() built-in function.

var_3 = 'east'
if isinstance(var_3, str):
    print(f'var_3 is of type str')

output

var_3 is of type str

Let us try to duplicate the exception message.

# Define our variables.
num_fruits_oranges = 7
num_fruits_apples = '3'

# Get the sum from our variables.
total_fruits = num_fruits_oranges + num_fruits_apples

print(f'total fruits: {total_fruits}')

output

Traceback (most recent call last):
  File "f:\Project\kodlogs\art4.py", line 7, in <module>
    total_fruits = num_fruits_oranges + num_fruits_apples
TypeError: unsupported operand type(s) for +: 'int' and 'str'

Caution TypeError: 'TypeError: unsupported operand type(s) for +: 'int' and 'str'

We have two operands, num_fruits_oranges of type int and num_fruits_apples of type str. The + operator attempts to add the operands. The TypeError occurred because Python does not support the addition between int and str objects.

2. How to avoid this error? #

To avoid this type of exception, we need to know the types of objects to add. If one object is a string and the other is an integer, we should not add them. Integers are whole numbers and can have a value of negative, positive and 0 values. Strings are characters enclosed in single and double quotes. A string can also be a single character, such as the letter 'a.'

If for some reason we don't know the type of a variable, we can use the isinstance() built-in function to check if it is an int.

code

def weird_function(isnumber=True):
    return 10 if isnumber else 'numeric'
    
# Get the value of the weird function.
value = weird_function()

# Check if value is an int or not.
if isinstance(value, int):
    print('value is of type int')
else:
    print('value is not of type int')

output

value is of type int

Once we know that the object is an int, we can then proceed with our addition operation.

There is a possibility that the operand is a numeric string, such as "10". In this scenario, we must first convert the str to an int object before doing any integer-specific operations.

code

# Ask the age, we expect a number.
num_years = input('How old are you? ')

print(f'num_years value is {num_years}')

# Assuming we dont' know the return type of the input function,
# we will use the isinstance() function to know if it is an int.
if isinstance(num_years, int):
    print('num_years is an int')
else:
    print('num_years is not an int')

    # Convert the numeric string to int.
    print('Convert the num_years str to int using int().')
    num_years_int = int(num_years)

    # Check the type of num_years_int.
    print(f'num_years_int is of type {type(num_years_int)}')

After the str is successfully converted to int using the built-in function int(), we can then continue operating on it.

sample output

How old are you? 54
num_years value is 54
num_years is not an int
Convert the num_years str to int using int().
num_years_int is of type <class 'int'>

FAQ

How to check if a variable or object type is int? Answer: Use the built-in function isinstance(variable, int). If it returns True, it is int.

How to know the type or class of a variable or object?
Answer: Use the built-in function type(variable).

What is the return type of an input() built-in function?
Answer: The return type is str.

3. Conclusion #

We will encounter the exception message TypeError: unsupported operand type(s) for +: 'int' and 'str' if we try to add an integer object with the string object. We can only add two or more operands if they are numeric such as int or float. We can avoid this errror by knowing the object type. We can use the isinstance() built-in function to check if the object is of type int or str. We can also determine the type or class of the object by using another built-in function type().

4. References #

Python-Dev. (n.d.-a). built-in-functions. Retrieved November 10, 2022, from https://docs.python.org/3/library/functions.html#built-in-functions
Python-Dev. (n.d.-b). input. Retrieved November 22, 2022, from https://docs.python.org/3/library/functions.html#input
Python-Dev. (n.d.-c). int. Retrieved November 22, 2022, from https://docs.python.org/3/library/functions.html#int
Python-Dev. (n.d.-d). isinstance. Retrieved November 22, 2022, from https://docs.python.org/3/library/functions.html#isinstance
Python-Dev. (n.d.-e). Text Sequence Type - str. Retrieved November 22, 2022, from https://docs.python.org/3/library/stdtypes.html#textseq
Python-Dev. (n.d.-f). type. Retrieved November 16, 2022, from https://docs.python.org/3/library/functions.html#type
Python-Dev. (n.d.-g). TypeError. Retrieved November 15, 2022, from https://docs.python.org/3/library/exceptions.html#TypeError

Coder Legion - Recent posts tagged string

Write a java program to count the letters, spaces, numbers and other characters of an input string.

Unity Devs: Stop Starving Your Frame Rate!

Unity Devs: Stop Starving Your Frame Rate! Embrace Modern Memory Discipline

Code Layout & Walkthrough: Taming Allocations

1. String Operations: Beyond Basic Concatenation

2. Dynamic Collections & Array Pooling

3. LINQ’s Hidden Costs

Conclusion

Convert the string into Camel case and remove special characters from string in C, C++

Table of Contents

1. Identify the problem#

2. Solution #

1. Solution in C++

2. Solution in C

3. Conclusion#

4. Reference#

All about the function which is used to parse a string to int

Parsing String to int in C:

Parsing String to int in C++:

Parsing String to Int in Java:

Parse String to Integer in C#:

Convert.ToInt():

Int32.Parse():

Parse String to Int in Python:

TypeError: unsupported operand type(s) for +: 'int' and 'str' in Python

Table of Contents

1. What is the problem? #

2. How to avoid this error? #

3. Conclusion #

4. References #