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javascript instance method

TypedArray.prototype.indexOf()

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The indexOf() method of TypedArray instances returns the first index at which a given element can be found in the typed array, or -1 if it is not present. This method has the same algorithm as indexOf().

Interactive exampleOpen the canonical MDN source to run this embedded demo.
const uint8 = new Uint8Array([10, 20, 30, 40, 50]);

console.log(uint8.indexOf(50));
// Expected output: 4

// From position 3
console.log(uint8.indexOf(20, 3));
// Expected output: -1

console.log(uint8.indexOf(51));
// Expected output: -1

Syntax

indexOf(searchElement)
indexOf(searchElement, fromIndex)

Parameters

  • searchElement
    • : Element to locate in the typed array.
  • fromIndex Optional

Return value

The first index of searchElement in the typed array; -1 if not found.

Description

See indexOf() for more details. This method is not generic and can only be called on typed array instances.

Examples

Using indexOf()

const uint8 = new Uint8Array([2, 5, 9]);
uint8.indexOf(2); // 0
uint8.indexOf(7); // -1
uint8.indexOf(9, 2); // 2
uint8.indexOf(2, -1); // -1
uint8.indexOf(2, -3); // 0

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.

See also