Find Student Grade Using If-Else Ladder in C

This program determines a student’s grade based on marks obtained, using an if-else ladder.

C Program

#include <stdio.h>

int main() {
    float marks;

    printf("Enter marks obtained (out of 100): ");
    scanf("%f", &marks);

    if (marks < 0 || marks > 100) {
        printf("Invalid marks.\n");
    }
    else if (marks >= 90) {
        printf("Grade: A+\n");
    }
    else if (marks >= 80) {
        printf("Grade: A\n");
    }
    else if (marks >= 70) {
        printf("Grade: B\n");
    }
    else if (marks >= 60) {
        printf("Grade: C\n");
    }
    else if (marks >= 40) {
        printf("Grade: D\n");
    }
    else {
        printf("Grade: F (Fail)\n");
    }

    return 0;
}

Explanation

• Each else if checks a progressively lower marks threshold — the first true condition determines the grade.
• Because the checks go from highest to lowest, a student scoring 95 correctly matches the first branch (>= 90) and skips the rest.
• Marks below 40 fall through to the final else, which marks the student as failed.
• An initial validity check rejects out-of-range input.

Sample Output

Enter marks obtained (out of 100): 76
Grade: B