27 lines
823 B
JavaScript
27 lines
823 B
JavaScript
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//#region src/predicate/isUndefined.ts
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/**
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* Checks if the given value is undefined.
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*
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* This function tests whether the provided value is strictly equal to `undefined`.
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* It returns `true` if the value is `undefined`, and `false` otherwise.
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*
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* This function can also serve as a type predicate in TypeScript, narrowing the type of the argument to `undefined`.
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*
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* @param {unknown} x - The value to test if it is undefined.
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* @returns {x is undefined} true if the value is undefined, false otherwise.
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*
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* @example
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* const value1 = undefined;
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* const value2 = null;
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* const value3 = 42;
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*
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* console.log(isUndefined(value1)); // true
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* console.log(isUndefined(value2)); // false
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* console.log(isUndefined(value3)); // false
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*/
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function isUndefined(x) {
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return x === void 0;
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}
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//#endregion
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exports.isUndefined = isUndefined;
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