Datatypes#

Here are the following common datatypes in JavaScript,

  • Number

  • String

  • Boolean

  • Symbol

  • Object

    • Function

    • Array

    • Date

    • RegExp

  • null

  • undefined

Numbers#

Since there are a single type of number there must be some compromises in the size. Numbers are initially a 32-bit integer but officially a 64-bit double precision float.

  • Math operations uses arithmetic operators as expected but there exist an object called Math that has methods like Math.sin

  • You may parse String, binary, hexadecimal, etc using parseInt, parseFloat, or in generally you can use the unary operator + to parse to number. For instance,

    + '0x10'; // 16

  • Operations with number may return NaN (not null) for cases that are not Infinity or -Infinity (which are other number types).

Strings#

Almost exactly like Java.

Boolean#

Uses the “truthy” and “falsy” concept that Python uses.