Yahoo! JAPAN

2020/4/2 -var declarations are globally scoped or function scoped while let and const are block scoped. · var variables can be updated and re-declared ...

Variables declared with var are hoisted but initialized with undefined . Variables declared with let and const are also hoisted, but not initialized.

2022/3/26 -Let is for a variable that you may want to change later. Const is for variables you do not want to change i.e. pi, date, name etc..

2026/6/25 -When to Use let and const · Use let when you know a variable's value might change later in your code. · Use const for variables that should ...

2023/9/19 -If you need to reassign a variable, use let; if you wish to declare constants, use const. You may build cleaner, more reliable JavaScript code ...

2023/4/13 -In my opinion nowadays it is better to use let and const. According to the ES6 standard, these options are more convenient with their scope.

2025/1/6 -Prefer const by default for variable declarations, and only use let when you know the value will need to change. Use const to define constants ...

In modern JavaScript, it's generally recommended to use const by default for variables that don't need to be reassigned. · Use let when you need to reassign a ...

Finally the difference between let and const is that once you've assigned a value to const , you can't reassign it, but with let , you can. var VS let VS const.