strcmp and strncmp in C: solved string-comparison exercise

strcmp and strncmp in C: solved string-comparison exercise

This exercise is scheduled for daily publication and follows the same didactic structure used across the site: clear statement, compilable code, and expected output.

Problem statement

Implement a practical example of the topic and validate the output in the console.

C solution

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

int main(void) {
    const char *a = "casa";
    const char *b = "caso";

    printf("strcmp: %d\n", strcmp(a, b));
    printf("strncmp(3): %d\n", strncmp(a, b, 3));
    return 0;
}

Expected output

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strcmp: -1
strncmp(3): 0

Common mistakes

  • Not validating input and standard-library return values.
  • Ignoring edge cases (buffers, limits, null pointers).
  • Skipping basic compile/run verification.

Practical use

strcmp and strncmp are used for key comparison, string sorting, and password validation in C applications.

Guided practice and full book

If you want a complete path with progressive difficulty:

FAQ

Is this exercise useful for C exams and technical interviews?

Yes. It targets patterns that commonly appear in practice assignments, technical interviews, and C programming exams.

Where can I keep practicing with more solved C exercises?

In Programming in C in 100 Solved Exercises and C Exercises. Kindle Unlimited: View on Amazon.

How should I practice this exercise type to improve faster?

Start with small inputs, run edge cases (empty, one item, max capacity), then rewrite the solution from scratch without copying.