Q: Does logical operators in C language are evaluated with short circuit?  

Answer: A

Option A

A: Yes, logical operators in the C language are evaluated using short-circuit evaluation. Short-circuit evaluation means that the evaluation of the second operand is skipped if the result of the entire expression can be determined by evaluating only the first operand.

In C, there are two main logical operators: && (logical AND) and || (logical OR). Here's how short-circuit evaluation works for each of them:

1. Logical AND (&&):
   • If the left operand is false (0), the overall expression is false, and the right operand is not evaluated because the result is already determined.
   • If the left operand is true (non-zero), the right operand is evaluated only if the left operand doesn't guarantee the overall result. This is because if the left operand is true, the overall expression's truth value depends on the right operand.

Example:

if (a > 0 && b > 0) {
    // Both a and b are evaluated, but only if a > 0 is true
}

2. Logical OR (||):
   • If the left operand is true (non-zero), the overall expression is true, and the right operand is not evaluated because the result is already determined.
   • If the left operand is false (0), the right operand is evaluated only if the left operand doesn't guarantee the overall result. This is because if the left operand is false, the overall expression's truth value depends on the right operand.

Example:

if (x == 0 || y == 0) {
    // Both x and y are evaluated, but only if x == 0 is false
}

Using short-circuit evaluation can have performance implications and can be used to optimize code. For example, if you have a conditional statement where the second operand's evaluation is costly, you can place it as the right operand of a logical AND operator so that it's evaluated only if necessary.

Keep in mind that short-circuit evaluation behavior may vary across programming languages, so it's important to understand the specific behavior of logical operators in the language you are using.

Click me to Read more Question & Answer of Operators and Enums in C Language

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