Using a global variable in a function in javascript

Question

I want to define a variable (Boolean), and then use it in a function two times. I started with defining a global variable, and then use this variable locally in my function as follows:

var  inpLock = false;
…
function doSomething(inpLock) {
    inpLock = true;
    switch …
        case
        case
    inpLock = false;
}

What happens by running this is: it sets the variable to true but not back to false. If I declare the variable inside the function like: var inpLock it also won’t work. Any help will be appreciated.

Can you reproduce it and give a link of jsfiddle of same thing? — Ishwar Rimal
– Ishwar Rimal, Commented Aug 7, 2017 at 11:39

Quentin · Accepted Answer · 2017-08-07 11:10:51Z

1

Giving a name to a function argument (doSomething(inpLock)) declares a local variable of that name.

This masks any global variable with the same name.

Changes you make to the variable inside the function only touch the local variable and ignore the global.

Avoid reusing variable names in nested scopes. It causes confusion.

edited Aug 7, 2017 at 11:10

answered Aug 7, 2017 at 11:08

Quentin

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2 Comments

Holden Caulfield Over a year ago

How can I assign a value to a variable in a function and then access this value globally?

Quentin Over a year ago

@GhzJabb — (1) Stop creating a local variable with the same name. (2) Use its name.

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