I've been able to write to stdout using the fs phantomjs module, thus being able to write as binary:
var fs = require('fs');
var stream = fs.open('/dev/stdout', 'wb');
stream.write(String.fromCharCode(128));
stream.flush();
It is still pretty slow for large volume of data, for some reason.
Answer from julien_c on Stack OverflowMDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Uint8ClampedArray
Uint8ClampedArray - JavaScript - MDN Web Docs
July 10, 2025 - // From a length const uint8c = new Uint8ClampedArray(2); uint8c[0] = 42; uint8c[1] = 1337; console.log(uint8c[0]); // 42 console.log(uint8c[1]); // 255 (clamped) console.log(uint8c.length); // 2 console.log(uint8c.BYTES_PER_ELEMENT); // 1 // From an array const x = new Uint8ClampedArray([21, 31]); console.log(x[1]); // 31 // From another TypedArray const y = new Uint8ClampedArray(x); console.log(y[0]); // 21 // From an ArrayBuffer const buffer = new ArrayBuffer(8); const z = new Uint8ClampedArray(buffer, 1, 4); console.log(z.byteOffset); // 1 // From an iterable const iterable = (function* () { yield* [1, 2, 3]; })(); const uint8cFromIterable = new Uint8ClampedArray(iterable); console.log(uint8cFromIterable); // Uint8ClampedArray [1, 2, 3] Polyfill of Uint8ClampedArray in core-js · JavaScript typed arrays guide · TypedArray · ArrayBuffer · DataView · Was this page helpful to you?
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Uint8ClampedArray › Uint8ClampedArray
Uint8ClampedArray() constructor - JavaScript - MDN Web Docs
July 10, 2025 - // From a length const uint8c = new Uint8ClampedArray(2); uint8c[0] = 42; uint8c[1] = 1337; console.log(uint8c[0]); // 42 console.log(uint8c[1]); // 255 (clamped) console.log(uint8c.length); // 2 console.log(uint8c.BYTES_PER_ELEMENT); // 1 // From an array const x = new Uint8ClampedArray([21, 31]); console.log(x[1]); // 31 // From another TypedArray const y = new Uint8ClampedArray(x); console.log(y[0]); // 21 // From an ArrayBuffer const buffer = new ArrayBuffer(8); const z = new Uint8ClampedArray(buffer, 1, 4); console.log(z.byteOffset); // 1 // From an iterable const iterable = (function* () { yield* [1, 2, 3]; })(); const uint8cFromIterable = new Uint8ClampedArray(iterable); console.log(uint8cFromIterable); // Uint8ClampedArray [1, 2, 3] Polyfill of Uint8ClampedArray in core-js · JavaScript typed arrays guide · TypedArray · ArrayBuffer · DataView · Was this page helpful to you?
Top answer 1 of 2
1
I've been able to write to stdout using the fs phantomjs module, thus being able to write as binary:
var fs = require('fs');
var stream = fs.open('/dev/stdout', 'wb');
stream.write(String.fromCharCode(128));
stream.flush();
It is still pretty slow for large volume of data, for some reason.
2 of 2
0
The only sane way of printing to the console is using console.log(). The drawback is that it inserts a newline everytime you call it, so you can't just print every character separately. You have to build a string and print it afterwards. As you noted, you can convert every byte to char with String.fromCharCode().
Also, functions like Uint8ClampedArray.prototype.join() are not yet implemented.
var a = new Uint8ClampedArray([37, 38, 39]);
console.log([].map.call(a, function(v){
return String.fromCharCode(v);
}).join());
Note that Uint8ClampedArray is not available in PhantomJS 1.x.
console.log() doesn't work in binary mode, so it will split characters above the 127 code point into two bytes when printed. This happens only when printing. You can check with
String.fromCharCode(147).length; // 1
If you are willing to write a file, you can use the fs module to write it in binary:
var a = new Uint8ClampedArray([37, 38, 39]),
fs = require('fs');
var b = [].map.call(a, function(v){
return String.fromCharCode(v);
}).join("");
fs.write("img.dat", b, "wb");
Tabnine
tabnine.com › home › code library
Code Library - Tabnine
July 25, 2024 - Get the answers and suggestions you need from our AI code assistant. Get started in minutes with a free 90 day trial of Tabnine Pro.
MDN
mdn2.netlify.app › en-us › docs › web › javascript › reference › global_objects › uint8clampedarray
Uint8ClampedArray - JavaScript | MDN
February 18, 2022 - // From a length var uintc8 = new Uint8ClampedArray(2); uintc8[0] = 42; uintc8[1] = 1337; console.log(uintc8[0]); // 42 console.log(uintc8[1]); // 255 (clamped) console.log(uintc8.length); // 2 console.log(uintc8.BYTES_PER_ELEMENT); // 1 // From an array var arr = new Uint8ClampedArray([21,31]); console.log(arr[1]); // 31 // From another TypedArray var x = new Uint8ClampedArray([21, 31]); var y = new Uint8ClampedArray(x); console.log(y[0]); // 21 // From an ArrayBuffer var buffer = new ArrayBuffer(8); var z = new Uint8ClampedArray(buffer, 1, 4); // From an iterable var iterable = function*(){ yield* [1,2,3]; }(); var uintc8 = new Uint8ClampedArray(iterable); // Uint8ClampedArray[1, 2, 3] ... Want to fix the problem yourself?
JavaScripture
javascripture.com › Uint8ClampedArray
Uint8ClampedArray JavaScript API
Gets and sets the element in this at index. index should be between 0 and this.length - 1. Setting an element to a value less than 0 will store 0 and greater than 255 will store 255 in the array. ... Returns the underlying buffer for this Uint8ClampedArray.
W3cubDocs
docs.w3cub.com › javascript › global_objects › uint8clampedarray
Uint8ClampedArray - JavaScript - W3cubDocs
August 7, 2022 - // From a length const uint8c = new Uint8ClampedArray(2); uint8c[0] = 42; uint8c[1] = 1337; console.log(uint8c[0]); // 42 console.log(uint8c[1]); // 255 (clamped) console.log(uint8c.length); // 2 console.log(uint8c.BYTES_PER_ELEMENT); // 1 // From an array const x = new Uint8ClampedArray([21, 31]); console.log(x[1]); // 31 // From another TypedArray const y = new Uint8ClampedArray(x); console.log(y[0]); // 21 // From an ArrayBuffer const buffer = new ArrayBuffer(8); const z = new Uint8ClampedArray(buffer, 1, 4); console.log(z.byteOffset); // 1 // From an iterable const iterable = (function* () { yield* [1, 2, 3]; })(); const uint8cFromIterable = new Uint8ClampedArray(iterable); console.log(uint8cFromIterable); // Uint8ClampedArray [1, 2, 3] Polyfill of Uint8ClampedArray in core-js · JavaScript typed arrays guide ·
Java2s
java2s.com › ref › javascript › javascript-uint8clampedarray-buffer.html
Javascript Uint8ClampedArray buffer
The Javascript Uint8ClampedArray buffer property returns the ArrayBuffer referenced by a Uint8ClampedArray.
MDN
mdn2.netlify.app › en-us › docs › web › javascript › reference › global_objects › uint8clampedarray › uint8clampedarray
Uint8ClampedArray() constructor - JavaScript | MDN
February 18, 2022 - // From a length var uintc8 = new Uint8ClampedArray(2); uintc8[0] = 42; uintc8[1] = 1337; console.log(uintc8[0]); // 42 console.log(uintc8[1]); // 255 (clamped) console.log(uintc8.length); // 2 console.log(uintc8.BYTES_PER_ELEMENT); // 1 // From an array var arr = new Uint8ClampedArray([21,31]); console.log(arr[1]); // 31 // From another TypedArray var x = new Uint8ClampedArray([21, 31]); var y = new Uint8ClampedArray(x); console.log(y[0]); // 21 // From an ArrayBuffer var buffer = new ArrayBuffer(8); var z = new Uint8ClampedArray(buffer, 1, 4); // From an iterable var iterable = function*(){ yield* [1,2,3]; }(); var uintc8 = new Uint8ClampedArray(iterable); // Uint8ClampedArray[1, 2, 3] BCD tables only load in the browser · Starting with ECMAScript 2015, Uint8ClampedArray constructors require to be constructed with a new operator.
GitHub
github.com › stdlib-js › array-uint8c
GitHub - stdlib-js/array-uint8c: Uint8ClampedArray. · GitHub
Creates a new typed array view over the same underlying ArrayBuffer and with the same underlying data type as the host array. var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] ); var arr2 = arr1.subarray(); // returns <Uint8ClampedArray>[ 1, 2, ...
Author: stdlib-js
GitHub
github.com › lovell › sharp › issues › 549
Pipe buffer image data into Uint8ClampedArray format · Issue #549 · lovell/sharp
August 22, 2016 - The .data property of the ImageData object appears to be a Uint8ClampedArray that reads [r1, g1, b1, a1, r2, g2, b2, a2.....] Looking at the pattern, every fourth number is 255 which makes sense as none of the image is transparent at all. I am trying to get this to work in Node.JS in a similar fashion, except I am getting my image data from a buffer generated by smarp see code below:
Author: lovell
Bun
bun.com › guides › binary data › arraybuffer to uint8array
Convert an ArrayBuffer to a Uint8Array | Bun Guides
const buffer = new ArrayBuffer(64); const arr = new Uint8Array(buffer);
UDN Web Docs
udn.realityripple.com › docs › Mozilla › js-ctypes › Using_js-ctypes › Working_with_ArrayBuffers
Working with ArrayBuffers - UDN Web Docs: MDN Backup
// pixelBuffer is a pointer to ... imgHeight = 400; var myImgDat = new ImageData(imgWidth, imgHeight); One method is to get into a js-ctypes array, and then set it into the ImageData, as illustrated by the following code example....
JavaScript.info
javascript.info › tutorial › binary data, files
ArrayBuffer, binary arrays
July 11, 2022 - let arr8 = new Uint8Array([0, 1, ... – for integer numbers of 8, 16 and 32 bits. Uint8ClampedArray – for 8-bit integers, “clamps” them on assignment (see below)....
Bun
bun.sh › guides › binary › arraybuffer-to-typedarray
Convert an ArrayBuffer to a Uint8Array - Bun
const buffer = new ArrayBuffer(64); const arr = new Uint8Array(buffer);
Reality Ripple
udn.realityripple.com › docs › Web › JavaScript › Reference › Global_Objects › Uint8ClampedArray
Uint8ClampedArray - JavaScript - UDN Web Docs: MDN Backup
// From a length var uintc8 = new Uint8ClampedArray(2); uintc8[0] = 42; uintc8[1] = 1337; console.log(uintc8[0]); // 42 console.log(uintc8[1]); // 255 (clamped) console.log(uintc8.length); // 2 console.log(uintc8.BYTES_PER_ELEMENT); // 1 // From an array var arr = new Uint8ClampedArray([21,31]); console.log(arr[1]); // 31 // From another TypedArray var x = new Uint8ClampedArray([21, 31]); var y = new Uint8ClampedArray(x); console.log(y[0]); // 21 // From an ArrayBuffer var buffer = new ArrayBuffer(8); var z = new Uint8ClampedArray(buffer, 1, 4); // From an iterable var iterable = function*(){ yield* [1,2,3]; }(); var uintc8 = new Uint8ClampedArray(iterable); // Uint8ClampedArray[1, 2, 3] The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Rust
docs.rs › js-sys › latest › js_sys › struct.Uint8ClampedArray.html
Uint8ClampedArray in js_sys - Rust
An Uint8ClampedArray() which creates an array with the given buffer but is a view starting at byte_offset for length elements. ... The fill() method fills all the elements of an array from a start index to an end index with a static value.