Javascript Definitions

strict mode

• Add the following line at the beginning of your script!

  'use strict';

• More information: JavaScript Use Strict

with

In the following example Math is added to the top of the scope chain and thus you don’t have to write Math.PI.

var a, x, y;
var r = 10;

with (Math) {
  a = PI * r * r;
  x = r * cos(PI);
  y = r * sin(PI / 2);
}

see with statement documentation.

Literal vs. Object

• Array Literal

  ['eat', 'bananas'];

• Array Object

  new Array('eat', 'bananas');

rest vs. spread operator ...

• rest operator gives you rest of input arguments as array. Should always occur at end of the list.
• spread operator splits array into single arguments for a function.

… spread operator documentation

bind()

Example from MDN:

In bind(context, [variable1, variable2, ...]) the context will be bound as this to the newly created bound function.

this.x = 9;
var module = {
  x: 81,
  getX: function () {
    return this.x;
  },
};

module.getX(); // 81

var retrieveX = module.getX;
retrieveX();
// returns 9. The function gets invoked at the global scope.

// Create a new function with 'this' bound to module
// New programmers might confuse the
// global var x with module's property x
var boundGetX = retrieveX.bind(module);
boundGetX(); // 81

call(), apply()

UNDERCONSTRUCTION_

apply()

Call function with certain value set as this value

apply() docs

ASI - Automatic semicolon insertion

See this SO thread and how prettier deals with it.

Dynamic typing

• Dynamic typing (JS) vs. static typing (TS)