what does "===" imply in Javascript/Jquery?
Possible Duplicate:
JavaScript === vs == : Does it matter which “equal” operator I use?
The 3 different equals
I'm trying to understand what is happening here:
data.toPage = $('div#someID');
if ( typeof data.toPage === "string" ) {
// sth
console.log("hello");
}
So I'm checking for a string am I not? I'm curious because my console "helloes".
Thanks for some input!
== This is the equal operator and returns a boolean true if both the operands are equal. JavaScript will attempt to convert different data types to the same type in order to make the comparison. Assuming 'a' to be 2 and 'b' to be 4, the following examples will return a value of true:
a == 2
a == "2"
2 == '2'
=== This is the strict equal operator and only returns a Boolean true if both the operands are equal and of the same type. These next examples return true:
a === 2
b === 4
===比较运算符意味着这两个值在进行比较之前不会修改它们的类型，所以它们需要具有相同的类型以及表示相同的值才能返回true。
'1' == 1 // true
'1' === 1 // false
The triple equals sign === compares both value and type, whereas the double == only compares value
for example "1" and 1 have the same value (so to speak) but are of different types. Therefore the following will occur:
"1" == 1 //true
"1" === 1 //false
This is a great read for some useful javascript knowledge, which includes the triple equals amongst other good-to-know stuff
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