May 2018
Intermediate to advanced
376 pages
9h 22m
English
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Lesson 4. Declaring variables with let
After reading lesson 4, you will
- Understand how scope works with let and how it differs from var
- Understand the difference between block scope and function scope
- Understand how let variables are hoisted
In the history of JavaScript, variables have always been declared using the keyword var.[1] ES6 introduces two new ways to declare variables, with the let and const keywords.[2] Both of these work slightly differently than variables declared with var. There are two primary differences with let:
Actually, in non-strict mode, it was possible to create a new variable while completely omitting the var declaration altogether. This, however, created a global, usually unbeknownst to the author, leading ...
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