Java program: Find the frequency of each character in the string

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

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

Java program: Find the frequency of each character in the string — Find the frequency of each character in the string

Code to find the frequency of the each character in the given string

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

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

program 1

//program to count the frequency of each character of the given string
import java.util.Scanner;
public class Count_frequency{
public static void main(String args[]){
//variable declaration 
    String str=" ";
int count=0,length=0,num=0;
//vriable declaration and initialization
 Scanner scan=new Scanner(System.in); 
    //create a scanner object for input
    
System.out.println("Enter the String  ");
str=scan.nextLine();
length=str.length();

for(int i=0; i<length; i++){
count=0;
   for(int j=0; j<length; j++){
       if(str.charAt(j)==str.charAt(i))
       count++;
   }
   for(int k=0; k<i; k++){
       if(str.charAt(k)==str.charAt(i))
       num=1;
   }
       if(num!=1)
         System.out.print(str.charAt(i)+" is occured: "+count+"times"+"\n");
     num=0;
   }
}
}

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

find the frequency of the each character in the string using while loop

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

program 2

//program to count the frequency of each character of the given string
import java.util.Scanner;
public class Count_frequency1{
public static void main(String args[]){
//variable declaration 
    String str=" ";
int count=0,length=0,num=0;
//vriable declaration and initialization
 Scanner scan=new Scanner(System.in); 
    //create a scanner object for input
    
System.out.println("Enter the String  ");
str=scan.nextLine();
length=str.length();

int i=0;
while(i<length){
count=0;
int j=0; 
   while(j<length){
       if(str.charAt(j)==str.charAt(i))
       count++;
    j++;
   }
   int k=0; 
   while(k<i){
       if(str.charAt(k)==str.charAt(i))
       num=1;
    k++;
   }
       if(num!=1)
         System.out.print(str.charAt(i)+" is occured: "+count+"times"+"\n");
     num=0;
      i++;
   }
}
}

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

find the frequency of the each character in the string using do-while loop

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

program 3

//program to count the frequency of each character of the given string
import java.util.Scanner;
public class Count_frequency2{
public static void main(String args[]){
//variable declaration 
    String str=" ";
int count=0,length=0,num=0;
//vriable declaration and initialization
 Scanner scan=new Scanner(System.in); 
    //create a scanner object for input
    
System.out.println("Enter the String  ");
str=scan.nextLine();
length=str.length();

int i=0;
do{
count=0;
int j=0; 
   do{
       if(str.charAt(j)==str.charAt(i))
       count++;
    j++;
   }while(j<length);
   int k=0; 
   do{
       if(str.charAt(k)==str.charAt(i))
       num=1;
    k++;
   }while(k<i);
       if(num!=1)
         System.out.print(str.charAt(i)+" is occured: "+count+"times"+"\n");
     num=0;
      i++;
   }while(i<length);
}
}

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