Stability: 0 - Deprecated: Use value === undefined instead.

    • object {any}
    • Returns: {boolean}

    Returns true if the given object is undefined. Otherwise, returns false.

    1. const util = require('util');
    3. const foo = undefined;
    4. util.isUndefined(5);
    5. // Returns: false
    6. util.isUndefined(foo);
    7. // Returns: true
    8. util.isUndefined(null);
    9. // Returns: false