February 2018
Intermediate to advanced
298 pages
8h 22m
English
Content preview from Learn ECMAScript - Second Edition
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The JavaScript data types
JavaScript variables hold (or store) data (or values). The type of data variables that they hold is called the data type. In JavaScript, there are seven different data types: number, string, Boolean, null, undefined, symbol, and object.
When it comes to holding objects, variables hold the object reference (that is, the memory address) instead of the object itself. If you're coming from a C/C++ background, you can relate them to pointers, but not exactly.
All data types other than objects are called primitive data types.
The arrays and functions are actually the JavaScript objects. A lot of things are objects under the hood.
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