Find Frequency of Each Character Dry Run in C

Find Frequency of Each Character is an interactive C dry run visualizer from the Strings programs section. Study the source code, then use the execution controls to follow each step, variable update, highlighted line, and console output.

This page provides a browser-based dry run with source-code highlighting, auto-scroll, voice narration controls, and execution output for learning the program step by step.

Find Frequency of Each Character Program Code

#include <stdio.h>
int main() {
    char str[] = "hello";
    int freq[256] = {0};
    int printed[256] = {0};
    int i = 0;
    
    while(str[i] != '\0') {
        freq[(int)str[i]]++;
        i++;
    }
    
    printf("Character frequencies:\n");
    i = 0;
    while(str[i] != '\0') {
        int ascii = (int)str[i];
        if(printed[ascii] == 0) {
            printf("'%c' : %d\n", str[i], freq[ascii]);
            printed[ascii] = 1;
        }
        i++;
    }
    
    return 0;
}

View the complete Strings programs page.