EN
JavaScript - what is the difference between let and var?
1
points
1. Main differences between let and var keywords are:
letkeyword varialbes do not have varialble hoisting.
variable hoisting is shifting varialbe declarations to top of source code making them accessible above.
Example 1:<!doctype html> <html> <body> <script> 'use strict'; a = 2; // variable hosting allows for assigning before declaration console.log(a); var a; </script> </body> </html>Output:
2
Example 2:<!doctype html> <html> <body> <script> 'use strict'; var a = 2; console.log(a); </script> </body> </html>Output:
2letkeyword varialbes can be created in different scopes:letkeyword variablesvarkeyword variablesglobal scope yes yes function scope yes yes curly braces scope yes no
2. Tips
- ALWAYS use
letkeyword.
