Iterating array in Javascript

Question

I would like to parse it and find if two value exist only once within this array.

Example: "text-success" OR "muted" if EXIST ONCE return the array

if it EXIST twice retrun null

example:

Array[6]
0:"text-warning"
1:"text-success"
2:"text-warning"
3:"text-success"
4:"muted"
5:"text-warning"
Array[6]
0:"text-warning"
1:"text-warning"
2:"text-warning"
3:"text-warning"
4:"text-success"
5:"text-warning"
Array[6]
0:"text-warning"
1:"text-warning"
2:"text-warning"
3:"text-success"
4:"muted"
5:"text-warning"
Array[6]
0:"text-warning"
1:"text-warning"
2:"text-warning"
3:"text-warning"
4:"muted"
5:"text-warning"

1st one will return FALSE because both exist "text-success"-twice AND "muted"-once

2nd one will return TRUE because it exist ONCE "text-success"

3rd one will return FALSE because both exist "text-success" AND "muted"

4th one will return TRUE because it exist ONCE "muted"

. . . .

and so on

so far this is my Javascript:

function singles( array ) {
 for( var index = 0, single = []; index < array.length; index++ ) {
 if( array.indexOf( array[index], array.indexOf( array[index] ) + 1 ) == -1 ) single.push( array[index] ); 
 };
 return single;
};

it is not working

please help.

Answer 1

You could use a simple loop with a counter as follows :

var count = 0;
for(i=0;i<arr.length;i++) {
if(arr[i] == "test-success" || arr[i] == "muted") {
count++;
}
if(count == 1) {
//process array data;
}

• Malarivtan: the code looks cool, but what if Both "test-success" and "muted" exist then it should not count
• Alan: In the 3rd example above muted and success exits once each and the result is false, in this case count will be 2 and thus result false. Only if either muted or success exist once only will it be true. Is this not the case?
• Malarivtan: var count = 0; for( var index = 0, single = []; index < array.length; index++ ) { if(array[index] == "test-success" || array[index] == "muted") { count++; } if(count == 1) { single.push(array[index]); } } return single
• Alan: the if(count == 1) needs to be outside the for loop.