syntax in Javascript

Question

function togglePageElementVisibility(what)  
{  
    var obj = typeof what == 'object'  
    ? what : document.getElementById(what);  

    if (obj.style.display == 'none')  
        obj.style.display = 'block';  
    else  
        obj.style.display = 'none';  
    return false;  
}

I got this code from a website to hide and unhide part of a webpage. I've been trying to wrap my head around it but im not sure how to change the first part to an if and else statement instead of what it is. Can you help please?

https://msdn.microsoft.com/en-us/library/be21c7hw(VS.94).aspx — suvroc, Dec 15 '15 at 14:35
It is an 'if' (ternary conditional operator): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator — jolmos, Dec 15 '15 at 14:36
Possible duplicate of [How to use the ?: (ternary) operator in JavaScript](http://stackoverflow.com/questions/6259982/how-to-use-the-ternary-operator-in-javascript) — Reinard, Dec 15 '15 at 14:36

J. Kovacevic · Accepted Answer · 2018-01-05T10:50:29.097

3

In your example Ternary Operator is used.

condition ? if-true : if-false

var obj;
if (typeof what === 'object') {
  obj = what;
} else {
  obj = document.getElementById(what);
}

is equal to

var obj = (typeof what === 'object') ? what : document.getElementById(what);

edited Jan 05 '18 at 10:50

answered Dec 15 '15 at 14:36

J. Kovacevic

183
16

Thank you so much! You saved me! – Omar Alsuwaidi Dec 15 '15 at 14:50

syntax in Javascript

1 Answers1