jQuery $.inArray still passing value even if it checked for existence [closed]

Question

I am using $.inArray to check if value is in array. if it is not I want to add it, else do nothing.

var arrayValues = [1];

for (var i = 1; i <= 3; i++) {

    if($.inArray('1', arrayValues) === -1) {

        arrayValues.push(0+i);  

    }

}

I am getting data on ajax page load as valuesArray = [value, value2]; on second load I get valuesArray valuesArray = [value, value2, value3, value4]; on third load I get value again and it still pushing it to valuesArray as valuesArray = [value, value2, value3, value4, value];.

Can anyone explain what I am doing wrong?

Thank you!

Please see live example at jsfiddle.

Answer 1

Your problem is that you add the number 1 in the array but check for the presence of the string "1". They're not equal for $.inArray.

You could do this :

if($.inArray(1, arrayValues) === -1) { // <- test with a number, not a string
    arrayValues.push(0+i); // note that the 0+ here is useless
}

While 1=='1', 1!=='1' and $.inArray tests using === as can be seen in the source code :

inArray: function( elem, arr, i ) {
    var len;

    if ( arr ) {
        if ( core_indexOf ) {
            return core_indexOf.call( arr, elem, i );
        }

        len = arr.length;
        i = i ? i < 0 ? Math.max( 0, len + i ) : i : 0;

        for ( ; i < len; i++ ) {
            // Skip accessing in sparse arrays
            if ( i in arr && arr[ i ] === elem ) {
                return i;
            }
        }
    }

    return -1;
},

More information on == vs === on the MDN.

Answer 2

Your code sample never calls $.inArray. It has syntax errors because there are multiple unclosed parens.

if($.inArray('value', valuesArray) === -1) {

    valuesArray.push(value);  

}