C Program: Count People by Height and Weight Conditions

Written: August 22, 2026

Conditional counting is a staple loop exercise: read pairs of measurements and bump a counter when a rule matches.

This walkthrough keeps the logic small and readable so you can type it, run it, and then change one input at a time to see what happens.

What you will build

You will loop over n people, read height and weight, and count those who meet your threshold.

• Read n
• For each person read height and weight
• If condition true, increment count
• Print the count

Working C example

#include <stdio.h>

int main(void) {
    int n, i, count = 0;
    float h, w;

    printf("Number of people: ");
    scanf("%d", &n);

    for (i = 0; i < n; i++) {
        printf("Height (cm) and weight (kg): ");
        scanf("%f %f", &h, &w);
        /* Example rule: height > 150 and weight < 50 */
        if (h > 150.0f && w < 50.0f) {
            count++;
        }
    }

    printf("Matching people: %d\n", count);
    return 0;
}

How the logic works

Read the program top to bottom: includes and main first, then the statements that change variables, then the print that proves the result.

If your output looks wrong, print the variables before and after the critical lines. That single habit catches most beginner bugs faster than rewriting the whole file.

Change the if-condition to match your assignment wording exactly — operators and units are where marks are lost.

Common mistakes

Forgetting a semicolon, using the wrong format specifier in printf/scanf, and mixing up assignment (=) with comparison (==) are the usual culprits.

Compile with warnings enabled (`gcc -Wall`) so the compiler points at risky casts and unused variables before you chase them by hand.

Try this next

Change the sample inputs, add a second test case, and briefly note what stayed the same. Teaching yourself with tiny experiments sticks better than copying a longer program you never run.

When you can explain every line without looking, you are ready for the next exercise in the series.

Keep learning

If this walkthrough on height weight condition c program helped, open the code again and change one input or assumption. Small experiments beat rereading the same example.

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