What does Short-Circuiting mean in TypeScript?

Short-circuiting in TypeScript, as in JavaScript, refers to the behavior of logical operators (&& and ||) during the evaluation of expressions, where the evaluation stops as soon as the outcome of the entire expression can be determined from the leftmost part of the expression. This means that in certain cases, not all parts of an expression will be evaluated, which can optimize performance by avoiding unnecessary computations.

Logical AND (&&) Short-Circuiting

For the logical AND (&&) operator, if the first operand evaluates to a falsy value, TypeScript knows the whole expression cannot possibly evaluate to true (since both operands must be true for the entire expression to be true). Therefore, it does not evaluate the second operand and returns the first falsy value it encounters. This behavior can be used to execute the second operand only if the first one is true[1][2][3].

Logical OR (||) Short-Circuiting

Conversely, for the logical OR (||) operator, if the first operand evaluates to a truthy value, the entire expression will definitely evaluate to true (since only one operand needs to be true for the entire expression to be true). Thus, TypeScript does not evaluate the second operand and returns the first truthy value it encounters. This can be utilized to provide default values or to execute the second operand only if the first one is false[1][2][3].

Practical Applications

Short-circuiting is often used in TypeScript for conditional execution and assignment. For example, it can be used to safely a...