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Which equals operator (== vs ===) should be used in JavaScript comparisons?
(48 answers)
JavaScript Equality Operator
(3 answers)
Closed 9 years ago.
Splitting hair here, but my editor complains I should use a !== null instead of a != null in a Javascript if statement. What is the difference?
Update
This question has been closed as duplicate, but the other questions supposedly answering my question are not answering it... Check their answers! There is a subtlety here -> null
Related
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Optional Chaining in JavaScript [duplicate]
(8 answers)
How does the JavaScript optional chaining(?.) operator works?
(2 answers)
Closed 10 months ago.
What does this mean
doc.data()?.email === auth.currentUser.email
?. <- what does this imply I saw it in a firebase project
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Variable position in comparision in PHP
(4 answers)
Why do some experienced programmers write comparisons with the value before the variable? [duplicate]
(12 answers)
PHP conditional assignment
(1 answer)
Closed 2 years ago.
In many place, I've seen that there is used the expression if (value === expression) rather than if (expression === value).
For example, In php we use-
if (false === strpos('abc', 'a'))
And also I see after minifying JavaScript, the minified file also generated like this.
So my question is, what is the benefit of value === expression over expression === value?
Note: This question may be redundant but I may not get the proper keywords for searching. If it is duplicated then I am ready to close the question.
I don't think there is a difference because the idea of equality operator is that to check if both sides are have the same value, in === also same type.
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What does this symbol mean in JavaScript?
(1 answer)
What's the significant use of unary plus and minus operators?
(2 answers)
Closed 2 years ago.
I have problem with understanding this code. I know what it do, but I dont understand the "+" after return.
function descendingOrder(n) {
return +n.toString().split('').sort().reverse().join('');
}
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What is the !! (not not) operator in JavaScript?
(42 answers)
Closed 7 years ago.
Maybe I am too quick in asking this question , but I was going through angular code and I found the logical expression evaluation like this :
https://github.com/angular/angular.js/blob/master/src/ng/directive/attrs.js#L362
Essentially an attribute was evaluated like :
attr.$set(attrName, !!value);
Is there a particular reason why was this done this way ?
!! is a concise way of ensuring that value will be a boolean.
This question already has answers here:
What is the !! (not not) operator in JavaScript?
(42 answers)
Closed 7 years ago.
Such as if(!!you) , I thought we can get rid of the !! , and it's the same. Cause JavaScript will change it to Boolean automatically?
!! cast the variable to a Boolean. Similar to how you do +foo to cast it to a number.