C String Program Remove Blank Spaces

/*
C Program to removing blank spaces from string

     easyCodeBook.com
*/

#include <stdio.h>
int main()
{
char str1[100], str2[100];
int i, j, size = 100;
printf("Enter a string to remove spaces:\n");
gets(str1);

j=0;
for(i=0; str1[i] != '\0'; i++)
 if(str1[i] != ' ')
   {
     str2[j] = str1[i];
     j++;
   }
   
   str2[j]='\0';

printf("String with out blank spaces is: \n");
puts(str2);
return 0;
}

Enter a string to remove spaces:
Hello World
String with out blank spaces is:
HelloWorld

Explanation of Logic

The given C program removes blank spaces from a string. It reads a string from the user, iterates through each character, and copies non-space characters to a new string. Finally, it prints the modified string without blank spaces.

1. The program starts with a multi-line comment providing a description of the program.
2. The code includes the standard input/output library stdio.h.
3. The main function is defined as the entry point of the program.
4. Inside the main function, several variables are declared:
   • char str1[100] and char str2[100] are arrays of characters. str1 is the original string, and str2 will store the modified string without blank spaces.
   • int i and int j are integer variables used as indices for iterating through the characters of the strings.
   • int size is an integer variable initialized to 100, which represents the maximum size of the strings.
5. The printf function is used to display a prompt message asking the user to enter a string to remove spaces.
6. The gets function is used to read a line of input from the user and store it in the str1 array.

7. The code enters a for loop that iterates through each character of the str1 string until the null character '\0' is encountered, indicating the end of the string.
8. Inside the loop, an if condition checks if the current character str1[i] is not a space ' '. If the condition is true, the character is copied to the str2 string at index j, and j is incremented.
9. After each iteration, the indices i and j are incremented to move to the next character in the str1 string and the next available position in the str2 string, respectively.

10. After the loop finishes, the null character '\0' is explicitly added to the str2 string at index j to mark the end of the string.
11. The printf function is used to display a message indicating that the string without blank spaces is about to be printed.
12. The puts function is used to print the modified string str2, which contains the original string without any blank spaces.
13. The return 0; statement indicates the end of the main function, and it signifies that the program execution was successful.