TypedArray.prototype.join()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2016.

The join() method of TypedArray instances creates and returns a new string by concatenating all of the elements in this typed array, separated by commas or a specified separator string. If the typed array has only one item, then that item will be returned without using the separator. This method has the same algorithm as Array.prototype.join().

Try it

const uint8 = new Uint8Array([10, 20, 30, 40, 50]);

console.log(uint8.join());
// Expected output: "10,20,30,40,50"

console.log(uint8.join(""));
// Expected output: "1020304050"

console.log(uint8.join("-"));
// Expected output: "10-20-30-40-50"

Syntax

js
join()
join(separator)

Parameters

separator Optional

A string to separate each pair of adjacent elements of the typed array. If omitted, the typed array elements are separated with a comma (",").

Return value

A string with all typed array elements joined. If array.length is 0, the empty string is returned.

Description

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

Examples

Using join()

js
const uint8 = new Uint8Array([1, 2, 3]);
uint8.join(); // '1,2,3'
uint8.join(" / "); // '1 / 2 / 3'
uint8.join(""); // '123'

Specifications

Specification

ECMAScript® 2027 Language Specification
# sec-%typedarray%.prototype.join

Browser compatibility

Enable JavaScript to view this browser compatibility table.

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Standard built-in objects
TypedArray
Static methods
1. from()
2. of()
Static properties
1. BYTES_PER_ELEMENT
2. [Symbol.species]
Instance methods
1. at()
2. copyWithin()
3. entries()
4. every()
5. fill()
6. filter()
7. find()
8. findIndex()
9. findLast()
10. findLastIndex()
11. forEach()
12. includes()
13. indexOf()
14. join()
15. keys()
16. lastIndexOf()
17. map()
18. reduce()
19. reduceRight()
20. reverse()
21. set()
22. slice()
23. some()
24. sort()
25. subarray()
26. toLocaleString()
27. toReversed()
28. toSorted()
29. toString()
30. values()
31. with()
32. [Symbol.iterator]()
Instance properties
1. buffer
2. byteLength
3. byteOffset
4. length
Inheritance
Object/Function
Static methods
1. apply()
2. bind()
3. call()
4. toString()
5. [Symbol.hasInstance]()
Static properties
1. displayName
2. length
3. name
4. prototype
5. arguments
6. caller
Instance methods
1. __defineGetter__()
2. __defineSetter__()
3. __lookupGetter__()
4. __lookupSetter__()
5. hasOwnProperty()
6. isPrototypeOf()
7. propertyIsEnumerable()
8. toLocaleString()
9. toString()
10. valueOf()
Instance properties
1. __proto__
2. constructor
Related pages
BigInt64Array
BigUint64Array
Float16Array
Float32Array
Float64Array
Int8Array
Int16Array
Int32Array
Uint8Array
Uint8ClampedArray
Uint16Array
Uint32Array