What is the Javascript equivalent of writing 'If not"

2018-06-26 19:09:07

This question already has an answer here:

Best way to find if an item is in a JavaScript array? [duplicate] 8 answers

How do I check if an array includes an object in JavaScript? 40 answers

The correct syntax is

if(!condition){
    expression();
}

Note that you need parenthesis around the condition.

@plalx wants a formal definition, and here you go:

IfStatement:
    if(Expression) Statement else Statement
    if(Expression) Statement

In case of any ambiguity the else would be matched with the nearest if .

If you have some value:

var excludeMe = "something unwanted";

Then you can use the following if statement:

if(myTestCase !== excludeMe) { //do something...}

Keep in mind that != does not check type and !== does check type. So, 1 != "1" is false and 1 !== "1" is true.

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