TextDecoder : Object

constructor

Decodes sequences of bytes into Strings.

Constructors

new TextDecoder() : TextDecoder

Constructs a new TextDecoder that decodes UTF-8 strings.

Example:

const decoder = new TextDecoder();
console.log(decoder.decode(new Uint8Array([240,159,152,128,240,159,144,177,226,154,189,239,184,143])));

Run

Results:

Spec

new TextDecoder(label : String, [options : Object]) : TextDecoder

options : {

fatal :	Boolean
ignoreBOM :	Boolean

}

Constructs a new TextDecoder. See https://encoding.spec.whatwg.org/#concept-encoding-get for valid label values.

Example:

const decoder = new TextDecoder('utf-16');

console.log(decoder.decode(new Uint16Array([0xd83d, 0xde00, 0xd83d, 0xdc31, 0x26bd, 0xfe0f])));

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Results:

Spec

Instance Properties

encoding : String readonly

Returns the effective encoding from the label specified during construction of this. See https://encoding.spec.whatwg.org/#concept-encoding-get for the mapping from label values to encodings.

Example:

const decoder = new TextDecoder();
console.log(decoder.encoding);

const decoder16 = new TextDecoder('utf-16');
console.log(decoder16.encoding);

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Results:

Spec

fatal : Boolean readonly

Example:

const decoder = new TextDecoder();
console.log(decoder.fatal);

const fatalDecoder = new TextDecoder('utf-8', { fatal: true });
console.log(fatalDecoder.fatal);

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Results:

Spec

ignoreBOM : Boolean readonly

Example:

const decoder = new TextDecoder();
console.log(decoder.fatal);

const ignoreBOMDecoder = new TextDecoder('utf-8', { ignoreBOM: true });
console.log(ignoreBOMDecoder.ignoreBOM);

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Results:

Spec

Instance Methods

decode 2 variants

decode(input : ArrayBufferView, [options : Object]) : String

options : {

stream :

Boolean

}

Decodes the bytes from input into a new String based on this.encoding. If options.stream is true, this will remember any partially consumed characters and apply them to the next decode() call.

Example:

const decoder = new TextDecoder();
const bytes = new Uint8Array([240,159,152,128,240,159,144,177,226,154,189,239,184,143]);
console.log(decoder.decode(bytes));

let i = 0;
const chunkSize = 3;
let res = '';
while (i < bytes.length) {
  res += decoder.decode(bytes.subarray(i, i + chunkSize), { stream: true });
  i += chunkSize;
}
res += decoder.decode(bytes.subarray(i));
console.log(res);

Run

Results:

Spec

decode(input : ArrayBuffer, [options : Object]) : String

options : {

stream :

Boolean

}

Example:

const decoder = new TextDecoder();
const bytes = new Uint8Array([240,159,152,128,240,159,144,177,226,154,189,239,184,143]);
console.log(decoder.decode(bytes.buffer));

Run

Results:

Spec

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