CODEWITHSUNDEEP
javascriptjqueryarrays
EmmyS
EmmyS

Reputation: 12138

How to determine if object is in array?

I have a javascript array that looks like this:

myFields = [
["fb-method","drop",false,"How did you order?"],
["fb-date","calendar",false,""],
["fb-time","drop",false,""],
["fb-location","drop",false,""],
["fb-amount","text default",false,""],
["fb-share","drop",false,""],
["fb-msg","textarea",true,""],
["next-btn","button",true,""]
]

I'm able to loop through the array and deal with specific bits like this:

len = fields.length;

//first check to make sure required fields are filled in
for(i=0; i<len; i++) {
     a = fields[i];
     if(a[0] != "fb-method") {
        // do stuff
    }
}

I need to be able to (outside the loop) do something if a specific element isn't part of the array, specifically one that looks like this:

["fb-location","drop",false,""]

I've tried using jQuery's .inArray function, but it returns true even when it should return false. See fiddle here.

What's the best way to go about this? jQuery or standard js is fine.

Upvotes: 1

Views: 115

Answers (3)

KooiInc
KooiInc

Reputation: 122906

Besides $.inArray you could use Array.filter on tmp this way:

if(  tmp.filter(function(a) {return -~a.indexOf('fb-location');}).length ) {
  // exists
}

JsFiddle

See also: Array.filter, Array.indexOf

Using JQuery, you'd use the JQuery grep method

if(  $.grep(tmp,function(a) {return -~a.indexOf('fb-location');}).length ) {
  // exists
}

Upvotes: 0

Dom
Dom

Reputation: 40459

$.inArray does not return a bool, it returns the index (if no match exists, it returns -1). You would want this statement (based on your jsfiddle):

if(jQuery.inArray("fb-location", tmp) > -1) {
    alert("it exists");
}
else {
    alert("it doesn't exist");
}

DEMO: http://jsfiddle.net/azWLC/2/

UPDATE:

As mentioned in the comments, this is only a half solution since the array is multidimensional. I recommend first using $.map():

var tmp = [
["fb-method","drop",false,"How did you order?"],
["fb-date","calendar",false,""],
["fb-time","drop",false,""],
["fb-amount","text default",false,""],
["fb-share","drop",false,""],
["fb-msg","textarea",true,""],
["next-btn","button",true,""]
];
var values = $.map(tmp, function(n, i){
    return n[0];
});

if(jQuery.inArray("fb-location", values) > -1) {
    alert("it exists");
}
else {
    alert("it doesn't exist");
}

DEMO: http://jsfiddle.net/azWLC/4/

Upvotes: 6

draxxxeus
draxxxeus

Reputation: 1523

jquery.inArray returns the index of the element. If it is not found it returns -1.. And any number except 0 is true and hence it says 'it exists'

Upvotes: 0

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