C program: find the frequency of given character in a string

In this article, we will discuss the concept of the C program: find the frequency of the given character in a string

In this post, we are going to learn how to find the frequency of the given character in the string in C programming language

Find the frequency of given character in a string

find the frequency of the given character in the string using for loop

The program allows the user to enter a String and then it finds the frequency of the given character in a string using for loop in C programing language

program 1

#include <stdio.h>
#include <stdlib.h>

int main()
{
    char str[100],ch;
    int fCount=0,i;

    printf("Enter a string!\n");
    fgets(str,sizeof(str),stdin);
    printf("Enter a character to find its frequency\n");
   scanf("%c",&ch);

   for(i=0; str[i]!='\0'; i++){
    if(ch==str[i]) fCount++;
   }
   printf("The frequency of %c is= %d",ch,fCount);
   getch();
    return 0;
}

When the above code is executed, it produces the following result

Enter a string
C language
Enter a character to find its frequency
a
The frequency of a is=2

Find the frequency of given character in a string using while loop

The program allows the user to enter a String and then it finds the frequency of the given character in a string using while loop in C programing language

Program 2

#include <stdio.h>
#include <stdlib.h>

int main()
{
    char str[100],ch;
    int fCount=0,i;

    printf("Enter a string!\n");
    fgets(str,sizeof(str),stdin);
    printf("Enter a character to find its frequency\n");
   scanf("%c",&ch);
i=0;
   while(str[i]!='\0'){
    if(ch==str[i]) fCount++;
    i++;
   }
   printf("The frequency of %c is= %d",ch,fCount);
   getch();
    return 0;
}

When the above code is executed, it produces the following result

Enter a string!
C programming language
Enter a character to find its frequency
g
The frequency of g is=4

Find the frequency of given character in a string using while loop

The program allows the user to enter a String and then it finds the frequency of the given character in a string using do-while loop in C programing language

Program 3

#include <stdio.h>
#include <stdlib.h>

int main()
{
    char str[100],ch;
    int fCount=0,i;

    printf("Enter a string!\n");
    fgets(str,sizeof(str),stdin);
    printf("Enter a character to find its frequency\n");
   scanf("%c",&ch);
i=0;
  do{
    if(ch==str[i]) fCount++;
    i++;}
    while(str[i]!='\0');
   printf("The frequency of %c is= %d",ch,fCount);
   getch();
    return 0;
}

When the above code is executed, it produces the following result

Enter a string!
C and Java are easy languages
Enter a character to find its frequency
a
The frequency of g is=7

Approaches

Declare a character array char str[100] and character variable char ch;
Declare and initialize integer variables as frequency=0;
The user asked to enter a string
The given string is stored in the variable str;
The user asked to enter a character
The given caracter is stored in the variable ch;
A loop(for, while and do-while) is used to count frequency of the character in the given string.
It is initialized as i=0, checks the condition whether str[i]!=’\0′); and executes the loop until the given condition becomes true
Use an if condition to test if(ch==str[i]), when the if statements is true, The frequency becomes frequency + 1( frequency = frequency +1);
When it is false, terminates the loop
Finally, the program displays the frequency of the given character of the given string