if(array.length===1) condition not working for array of length > 1

Question

I have an if-else within my main controller:

var entity = shareDataService.getModalEntity();

if (entity = "NULL" || entity.length === 1) {
    myDataPromise = getDataService.getDataFromREST(security);
    console.log("HERE")
} else {
    myDataPromise = $q.all(getDataService.keepICorrect(security));
    console.log("THERE")
};

It takes entities data from a service, shareDataService.

It works fine when entity.length === 1 or entity === "NULL", but when the array is of length 2 or more, the condition does not pass it to the else. I cannot work out for the life of my why, I have debugged just before the if-else to check the value passed to the controller's function, and the array is definitely of length 2+ when I intend it to be. Also debugging entity.length just before the if-else shows the correct length of the array. What am I missing?

Possible duplicate of [What is the correct way to check for string equality in JavaScript?](http://stackoverflow.com/questions/3586775/what-is-the-correct-way-to-check-for-string-equality-in-javascript) — notAChance, Dec 23 '15 at 15:02

Anik Islam Abhi · Accepted Answer · 2015-12-03T10:54:49.697

9

You are assigning values intead of comparing

entity = "NULL"

Try like this

entity == "NULL"

Sugession :

You can check falsy .

null,'',undefined,0,NaN consider falsy in javascript

Try like this

if(!entity || entity.length === 1)

edited Dec 03 '15 at 10:54

answered Dec 03 '15 at 10:40

Anik Islam Abhi

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@Sulthan not if comparing to a string – Jaromanda X Dec 03 '15 at 10:41
Bingo. How did I miss this. Thanks so much :) – notAChance Dec 03 '15 at 10:41
Just to reiterate, "==" if string, "===" for all else? – notAChance Dec 03 '15 at 10:42
Thanks for the suggestion, but the actual string "NULL" needs to be used if no array is detected, if a string is passed as "NULL" is it only a string or can it be considered falsy? – notAChance Dec 03 '15 at 10:44
@Nope "NULL" is not equal to null – Anik Islam Abhi Dec 03 '15 at 10:45
That's what I was thinking, thanks @AnikIslamAbhi – notAChance Dec 03 '15 at 10:46

score 1 · Answer 2 · answered Dec 03 '15 at 10:42

var entity = shareDataService.getModalEntity();

if (entity = "NULL" || entity.length === 1) {

Note the = instead of == or ===, you're assigning a value of "null" to entity which then evaluates to a truthy value, the || is short-circuiting so because the first expression evaluates to truthy the length === 1 part won't be evaluated, so the true branch of the if statement will always be executed.

if(array.length===1) condition not working for array of length > 1

2 Answers2