I’m so confused about how Void operator (in javascript) works and what is it’s role. as i read, Void is an operator that evaluate an expression without returning a value, but by executing that script for example:
<html>
<head>
</head>
<body>
<a href="javascript:void(alert(1+1))">Click me!</a>
</body>
</html>
After clicking on the link, the browser shows the value 2, which mustn’t be shown since the evaluated expression (alert(1+1)) shouldn’t return a value due to being an operand of the Void operator.
Can someone clear it up for me please?.
6
Return values and side effects are two different things. void eliminates the return value, it has no effect on side effects:
This operator allows inserting expressions that produce side effects into places where an expression that evaluates to undefined is desired.
alert() produces a window as a side effect, not a return value. 1+1 is an expression that does return a value, but that return value is handled by alert(), not the void operator.
Note that alert() might not return a value normally, it does not in Firefox 47, making the void wrapper redundant in this particular case.
0