Will JavaScript initialization be improved?

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JavaScript initialization does not promote

Only declared variables in JavaScript will be promoted, not initialized ones.

The results of the following two examples are different:

Example 1

Var x = 5; / / initialize x

Var y = 7; / / initialize y

Elem = document.getElementById ("demo"); / / find the element

Elm [XSS _ clean] = x + "" + y; / / display x and y

Example 2

Var x = 5; / / initialize x

Elem = document.getElementById ("demo"); / / find the element

Elm [XSS _ clean] = x + "" + y; / / display x and y

Var y = 7; / / initialize y

Example 2's y outputs undefined because the variable declaration (vary) is promoted, but initialization (yinitialization 7) is not promoted, so the y variable is an undefined variable.

Example 2 looks like the following code:

Var x = 5; / / initialize x

Var y; / / statement y

Elem = document.getElementById ("demo"); / / find the element

Elm [XSS _ clean] = x + "" + y; / / display x and y

Y = 7; / / set y to 7

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