Remove duplicate characters from a string Dry Run in C

Remove duplicate characters from a string is an interactive C dry run visualizer from the String Functions 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.

Remove duplicate characters from a string Program Code

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

int main() {
    char str[] = "programming";
    int len = strlen(str);
    int index = 0;
    int j;
    
    printf("Original: %s\n", str);
    
    for(int i = 0; i < len; i++) {
        // Check if character already appeared
        for(j = 0; j < i; j++) {
            if(str[i] == str[j]) {
                break;
            }
        }
        // If not found, keep it
        if(j == i) {
            str[index++] = str[i];
        }
    }
    str[index] = '\0';
    
    printf("After removing duplicates: %s\n", str);
    return 0;
}

View the complete String Functions programs page.