What is Triple equal operator? Where, Why & When it’s used?
In general,
Double equal (==) is called equality operator
Tripe equal (===) is called identity operator
Here are few gotchas, you would love reading!
Where it’s used?
Seems that in PHP, RUBY (I haven’t played with them, but got to know through googling :)) & JavaScript
Why & When it’s used?
When we have a situation to check “both operands have the same value and are of the same type”.
Let’s see some examples in JavaScript:
‘1’ === ‘1’ // true – Same value and type
‘1’ === 1 // false – Same value but different type
‘1’ === true // false – Value and type are different
Equality operators also have their opposites 🙂
The non-identity operator ( !== ) returns true, where identity would return false.
‘1’ !== ‘1’ // false
‘1’ !== 1 // true
Then, is anything there in C#?
I don’t see the exact, but we have one, that helps to check for the same “instance” type, that’s it!
C# static method ReferenceEquals(obj1, obj2), helps to check same instance or reference equality.
Reference:
http://www.color-of-code.de/index.php/articles/programming5/c-identity-vs-equality
Other useful references:
http://en.wikipedia.org/wiki/Equals_sign
http://stackoverflow.com/questions/359494/javascript-vs-does-it-matter-which-equal-operator-i-use