'==' is for numerical comparisons, which means both arguments will be converted to numbers before the actual comparison happens.

That's why you get warnings if the conversion fails ("foo" isn't numeric) or one of the values is undef.

The reason why perl has both stringwise and numerical comparisons,, is because you're not really supposed to know whether a scalar contains a string or a number. A value "1" is thought of as being equivalent to just 1. Other languages that have only one equality test operator, like Javascript, VB, and PHP, can cause bugs because it tries to infer what you mean from the type of variable. Which could be different from what you think. Ditto with the concatenation operator, . vs. +.

p.s. In the CB, jkva seems to have had some doubt on why == is called a "binary operator". The reason is because == has 2 arguments, plain and simple (bi == 2). Likewise, ! is an "unary operator" (un == 1), and ?: is a "ternary operator" (ter == 3).

In reply to Re: Equality operators by bart
in thread Equality operators by jkva

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