Variables defined using the let keyword in JavaScript have block-level scope and are only available within the block or function in which they are declared, preventing accidental overwriting and global pollution.
let defines variables in JavaScript
let is a keyword used to declare variables in JavaScript. It introduces a new kind of scope, which means that let variables declared in a block or function are only available within that block or function.
The difference between let and var
The main difference between let and var is the scope. Variables declared with var have function scope, which means they can be used within the scope of the function in which they are declared. On the other hand, variables declared by let have block scope, which means they can only be used within the block in which they are declared.
Using let
To declare a variable using let, use the following syntax:
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For example, to declare a variable named "name" For variables, you can use the following code:
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Advantages
Using let to declare variables has the following advantages:
Example
The following example demonstrates the scope of let:
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In this example, the x variable is declared inside the block, Therefore it is only available within the block. A ReferenceError is raised when trying to access the x variable outside the block.
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