Difference between revisions of "JavaScript"

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// then the first element will be your accumulator
 
// then the first element will be your accumulator
 
// I.e. the first call to your function will be (arr[0], arr[1])
 
// I.e. the first call to your function will be (arr[0], arr[1])
arr.reduce((acc, x) => acc + x, 0); //6
+
arr.reduce((acc, x) => acc + x, 0); // 6
 
</syntaxhighlight>
 
</syntaxhighlight>
  

Revision as of 14:33, 17 December 2019

This page is a mostly about browser-based JavaScript or ECMAScript usage and interaction with the HTML DOM (window). For server and desktop application JavaScript usage, please see the NodeJS page.

Usage

Arrays

let arr = [1,2,3];

// Map
arr.map(x => x > 2); // [false, false, true]

// Reduce or Fold
// Note that if you do not provide an initial accumulator,
// then the first element will be your accumulator
// I.e. the first call to your function will be (arr[0], arr[1])
arr.reduce((acc, x) => acc + x, 0); // 6

Canvas

Video

Regular Expressions (Regex)

Reference

var myRegex = /(\d+),(\d+)/;
var myStr = "124,52";
var match = myStr.match(myRegex);
// Captures
console.log(match[1], match[2]);
console.table(match);

Compilation

Modules