What are Logical Errors?

Logic errors, also known as bugs or semantic errors, occur when a program's logic is flawed or incorrect. Unlike syntax errors (detected by the compiler) or runtime errors (detected during program execution), logic errors do not prevent the program from running or generate error messages. Instead, they cause the program to produce unintended or incorrect results. Logic errors are typically the result of mistakes in the program's design or algorithm and can be challenging to identify and fix. Here are some common examples of logic errors:

1. Incorrect Calculation:

#include 

int main() {
    int x = 5;
    int y = 10;
    int sum = x - y; // Incorrect calculation
    printf("Sum: %d\n", sum);
    return 0;
}

In this example, the program is supposed to calculate the sum of x and y, but there is a logic error because subtraction is used instead of addition.

2. Off-by-One Errors:

#include 

int main() {
    int numbers[] = {1, 2, 3, 4, 5};
    int sum = 0;

    for (int i = 0; i <= 5; i++) { // Off-by-one error in loop
        sum += numbers[i];
    }

    printf("Sum: %d\n", sum);
    return 0;
}

This program attempts to calculate the sum of an array of numbers, but there is an off-by-one error in the loop condition. It will access an element beyond the array's bounds and produce incorrect results.

3. Incorrect Conditionals:

#include 

int main() {
    int x = 5;

    if (x = 0) { // Incorrect conditional assignment
        printf("x is zero\n");
    } else {
        printf("x is not zero\n");
    }

    return 0;
}

In this example, there is a logic error in the if statement. Instead of comparing x to zero, it assigns zero to x and always prints "x is zero."

#include 

int main() {
	int x = 5;

	while (x > 0) {
		printf("x is greater than zero\n");
		// Missing code to update the value of x
	}

	return 0;
}