Question

If the sub-expression on the left of the _______ logical operator is false, the right sub-expression is not checked.

Short answer

Answer: The logical operator responsible for short-circuit evaluation is the AND (`&&`) operator.

Step-by-step solution

Identifying the logical operator

The logical operator in question is the "AND" operator, represented by `&&` in many programming languages (e.g., C, C++, Java, JavaScript, etc.)

Understanding short-circuit evaluation

When using the AND (&&) operator in a compound logical expression, if the left sub-expression is false, there is no need to check the right sub-expression because the entire expression will be false regardless of the right sub-expression's value. This behavior is called short-circuit evaluation because it "short-circuits" or stops the evaluation process early when the result can already be determined.

Example of short-circuit evaluation with the AND (&&) operator

Consider the following compound logical expression:

(false) && (expr)

Since the left sub-expression is false, there is no need to evaluate `(expr)`, as the entire expression will be false regardless of the right sub-expression's value. Therefore, short-circuit evaluation occurs with the AND (&&) operator. In conclusion, the logical operator in question is the AND (`&&`) operator, as it prevents the right sub-expression from being evaluated if the left sub-expression is false.