Nested code blocks can be used to create a new scope: variables declared within that block cannot be accessed from the outside, and their lifetime
end at the end of the block. However, this only happens when you use ES6 let or const keywords, a class declaration or a
function declaration (in strict mode). Otherwise, the nested block is redundant and should be removed.
Exceptions
The rule does not apply to the following cases:
- Block statements containing variable declarations using
let or const keywords or class declarations are not redundant
as they create a new scope.
{
let x = 1;
}
- The same applies to function declarations in strict
mode
"use strict";
{
function foo() {}
}
- The rule also does not apply to the blocks that are part of the control flow.
if (condition) {
doSomething();
}
