Whether the let declaration in es6 can have the same name

This article mainly introduces "whether the let statement in es6 can be renamed". In the daily operation, I believe that many people have doubts about whether the let statement in es6 can be renamed. The editor consulted all kinds of materials and sorted out a simple and easy-to-use method of operation. I hope it will be helpful to answer the doubt of "whether the let statement in es6 can be renamed". Next, please follow the editor to study!

In es6, variables declared by let cannot have the same name, because let does not allow repeated declaration of the same variable in the same scope, otherwise an error will occur; therefore, let can be used to prevent duplicate variable naming and variable contamination; contrary to let, var,var allows variable declaration to be repeated.

This tutorial operating environment: windows10 system, ECMAScript version 6. 0, Dell G3 computer.

Can the let declaration in es6 be renamed?

Let declaration in es6 cannot be duplicated.

Let does not allow repeated declaration of the same variable within the same scope. Otherwise, report an error.

In the same scope, unlike var, you cannot use let to declare the same variable repeatedly

Function qq () {var a = 11; let a = 22;} / / SyntaxError:Identifier 'a'has already been declared (identifier a has been declared) function qq () {let a = 11; let a = 22;} / / SyntaxError:Identifier 'a'has already been declared (identifier'a' has been repeatedly declared)

There is no problem of repeating declaration errors when using var to declare variables. Repeat declarations can be made, but using let can prevent repetition of variable names and prevent variable contamination.

The error result is shown in the following figure:

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