CODEWITHSUNDEEP
javascript
redditor
redditor

Reputation: 4306

IF null ELSE - Correct syntax of If Else

I want to check if my json data is null/undefined. I have the following code but it seems to skip the checking and go straight to the else.

if (events === null) {
    container.append(nano(nogig));
} else {
    events[0].start.good_date = good_date(events[0].start.date);
    container.append(nano(template, events[0]));
}

Line 385 on this JSfiddle

http://jsfiddle.net/5WQxq/

Upvotes: 0

Views: 885

Answers (2)

nnnnnn
nnnnnn

Reputation: 150070

If you use the == operator rather than the === operator then testing against null will also match on undefined. That is undefined == null will return true, while undefined === null will return false. So try this:

if (events == null) {

Demo: http://jsfiddle.net/5WQxq/1/

Alternatively you can explicitly test for both values:

if (events === null || events === undefined) {

Or you can just test for a falsy value:

if (!events) {

(...which would also match on false, 0, empty string, and NaN, but those values aren't likely to apply and in any case if they did occur you'd still want the if case to match.)

Upvotes: 1

Typo
Typo

Reputation: 1910

if (!events) {
            container.append(nano(nogig));
        } else {
            events[0].start.good_date = good_date(events[0].start.date);
            container.append(nano(template, events[0]));
        }

This checks for null and undefined.

Upvotes: 3

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