When should you use === vs ==, !== vs !=, etc.. in javascript?
Possible Duplicate:
Javascript === vs == : Does it matter which “equal” operator I use?
What are the differences between === and ==, !== and ==... when should you use one and when should you use the other?
Matt
=== is the Identity operator, and is used to test that value and type are equal.
so..
"3" == 3 // true
"3" === 3 // false
1 == true // true
1 === true // false
"1" == true // true
"1" === true // false
so when you care that value and type are equal, or not equal use Identity operators === or !==
The "normal" == operators in javascript perform type coercion, and try their best to do things like treat a string as number or an object as a string where required. The longer === operators will not do type coercion, but rather a strict comparison within the type.
===和!==与==和!=相同，但还要检查变量类型。
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