Calculator Logic & Input Handling

A basic calculator accepts two operands and an operator character (+, -, *, /, %) and evaluates the expression cleanly using a C switch statement.

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C Source Code

c (ISO Standard)
Run in Compiler.cCopy
#include <stdio.h>
#include <stdbool.h>

bool calculate(double num1, char op, double num2, double *result) {
    switch (op) {
        case '+':
            *result = num1 + num2;
            return true;
        case '-':
            *result = num1 - num2;
            return true;
        case '*':
            *result = num1 * num2;
            return true;
        case '/':
            if (num2 == 0.0) {
                printf("Error: Division by zero is undefined.\n");
                return false;
            }
            *result = num1 / num2;
            return true;
        default:
            printf("Error: Unsupported operator '%c'.\n", op);
            return false;
    }
}

int main() {
    double a = 24.0, b = 6.0;
    char operators[] = {'+', '-', '*', '/', '?'};
    int count = sizeof(operators) / sizeof(operators[0]);

    printf("Executing Calculator Operations in C:\n\n");
    for (int i = 0; i < count; i++) {
        char op = operators[i];
        double res;
        if (calculate(a, op, b, &res)) {
            printf("  %.1f %c %.1f = %.2f\n", a, op, b, res);
        }
    }

    return 0;
}

Sample Output

text (ISO Standard)
Copy
Executing Calculator Operations in C:

  24.0 + 6.0 = 30.00
  24.0 - 6.0 = 18.00
  24.0 * 6.0 = 144.00
  24.0 / 6.0 = 4.00
Error: Unsupported operator '?'.

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Complexity Analysis

• Time Complexity: O(1) constant time arithmetic.
• Space Complexity: O(1) zero auxiliary memory.

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Related References

• Review arithmetic precedence in C Operators Reference.
• Learn conditional control flow in C Programming Basics.