26 lines
661 B
Markdown
26 lines
661 B
Markdown
### is
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Checks if the provided value is of the specified type (doesn't work with literals).
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Use the `instanceof` operator to check if the provided value is of the specified `type`.
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```js
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const is = (type, val) => val instanceof type;
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```
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```js
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is(Array, [1]); // true
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is(ArrayBuffer, new ArrayBuffer()); // true
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is(Map, new Map()); // true
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is(RegExp, /./g); // true
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is(Set, new Set()); // true
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is(WeakMap, new WeakMap()); // true
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is(WeakSet, new WeakSet()); // true
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is(String, ''); // false
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is(String, new String('')); // true
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is(Number, 1); // false
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is(Number, new Number(1)); // true
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is(Boolean, true); // false
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is(Boolean, new Boolean(true)); // true
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```
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