Posted in javascript
3450
6:39 am, May 19, 2020
 

javascript isset equivalent

i was just looking for an equivalent to the isset in php for javascript, i was initially using .length but this can still cause errors so i found this solution.
if (typeof my_var !== 'undefined') {}

Javascript

var my_var = "something";
if (typeof my_var !== 'undefined') {
var note = 'do something if my variable exists and has something in it';
console.log(note);
}
if (typeof not_my_var !== 'undefined') {
var note = 'this should not run or cause errors unless not_my_var has a value even though it it not declaired anywhere';
console.log(note);
}

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