C Program to find length of a string

Category: C ProgramTags: cprogram string

Write a C program to find the length of a string. How to find the length of a string in a C language.
We can use the following four methods to find the length of a string.

1. Using for loop
2. Using while loop
3. Using pointer
4. Using strlen function

C Program to find the length of a string using for loop

#include <stdio.h>

void main()
{
  char str[50];
  int i = 0, length = 0;

  printf("Enter the string: ");
  gets(str);

  for (i = 0; str[i] != '\0'; i++)
    length++;

  printf("Length of string is: %d", length);
}

C Program to find the length of a string using while loop

#include <stdio.h>

void main()
{
  char str[50];
  int i = 0, length = 0;

  printf("Enter the string: ");
  gets(str);

  while (str[length] != '\0')
    length++;

  printf("Length of string is: %d", length);
}

C Program to find the length of a string using pointer

#include <stdio.h>

void main()
{
  char str[50];
  char *p = str;
  int length = 0;

  printf("Enter the string: ");
  gets(str);

  while (*p != '\0')
  {
    length++;
    *p++;
  }

  printf("Length of string is: %d", length);
}

C Program to find the length of a string using strlen() function

#include <stdio.h>
#include <string.h>

void main()
{
  char str[50];
  char *p = str;
  int length = 0;

  printf("Enter the string: ");
  gets(str);

  length = strlen(str);

  printf("Length of string is: %d", length);
}

Output

Output

Enter the string: procoding
Length of string is: 9