Mistakes are part of the process

Find the bug. Understand the why.

Analyze your own C source or work through a separate set of guided debugging challenges.

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Static analysis — not compilation or execution

Enter any C source. This lightweight pattern scanner flags common punctuation, delimiter, condition, input, initialization and array-bound mistakes. It is not a full parser, cannot resolve headers or prove control flow, and can miss errors or produce false positives. No code is sent to a compiler, server or paid API.

</>Your code

10 lines · C

#include <stdio.h>

int main(void) {
    int total = 0;
    for (int i = 1; i <= 5; ++i) {
        total += i;
    }
    printf("Sum: %d\n", total);
    return 0;
}

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Six focused challenges

Punctuation · Guided fixed exercise

The missing semicolon

Correct line 3 only. These reference-line exercises are separate from the free-entry analyzer.

challenge.cC

1#include <stdio.h>2int main(void) {3    int count = 54    printf("%d\n", count);5    return 0;6}

0 / 6 challenges complete