Count vowels in C: solved exercise

Count vowels in C: solved exercise

This exercise is scheduled for daily publication and follows the standard site structure: statement, solution, and expected output.

Problem statement

Solve the practical case and verify the console output.

C solution

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#include <stdio.h>

int es_vocal(char c) {
    return c=='a'||c=='e'||c=='i'||c=='o'||c=='u'||
           c=='A'||c=='E'||c=='I'||c=='O'||c=='U';
}

int main(void) {
    char s[] = "Programacion";
    int c = 0;
    for (int i = 0; s[i] != '\0'; i++) if (es_vocal(s[i])) c++;
    printf("Vocales: %d\n", c);
    return 0;
}

Expected output

1

Vocales: 5

Common mistakes

  • Not validating standard-function return values.
  • Ignoring edge cases for indices, pointers, or buffers.
  • Skipping example-based test runs before publishing.

Practical use

Character counting is useful in form validation, linguistic analysis, and basic data compression.

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.