String manipulation is a major element of programming. In this shot, we will learn how to remove spaces from a string in C++.


#    
## Problem statement

Remove all spaces from a given string and return it. For example:
```c++
Input = "Edpresso: Dev    -Shot"
Output = "Edpresso:Dev-Shot"
```

#   
#  Algorithm

- Initialize the `non_space_count ` variable to `0`. This will maintain the frequency of the non-space characters in a string.

- Go over each character in a string one by one. If a character is `not a space`, place it at the `non_space_count` index and increment `non_space_count` by 1.

- Once done, place `\0` at the final `non_space_count` value that indicates the end of the string.

#   
## Time complexity
The time complexity of this algorithm is $O(n)$.

##  
## Code


#include <iostream>
using namespace std;
 
// Funtion removing spaces from string
char * removeSpacesFromStr(char *string)
{
    // non_space_count to keep the frequency of non space characters
    int non_space_count = 0;
 
    // Traverse a string and if it is non space character then, place it at index non_space_count
    for (int i = 0; string[i] != '\0'; i++)
        if (string[i] != ' ')
        {
            string[non_space_count] = string[i];
            non_space_count++; // non_space_count incremented
        }    
    
    // Finally placing final character at the string end
    string[non_space_count] = '\0';
    return string;
}
 
int main()
{
    char string[] = "Edpresso: Dev    -Shot";
    cout << string << "\n";
    cout << removeSpacesFromStr(string);
    return 0;
}

How to remove spaces from a string in C++

Problem statement

Algorithm

Time complexity

Code