How do I search a string in JavaScript array using jQuery? [duplicate]

Question

I have a JavaScript array:

var j_array = new Array();
j_arry=["class:1","division:a","class:5","class:3","division:b","division:c","division:d","class:10"];

I need to find how many times the class is coming and its array key, so I use:

found = $.inArray('class', j_array); ` But it returns `-1`;

Then I use:

var search = 'class';
$.each([j_array], function(index, value){
    $.each(value, function(key, cell){
        if (search.indexOf(cell) !== -1)
            console.log('found in array '+index, cell);
    });
});

But that is also wrong. How do I solve this?

From this array I want to get the following:

1. Class coming 4 times, at key 0, 2, 3, and 7

2. I want to make a separate array of class only, that is,

   new_array = ["class:1", "class:2", "class:3", "class:10"];
   

3. Currently there are four classes in j_array. How can I get the Nth class value

That is, 1st class value ="class:1", 2nd class value="class:5", etc.

Answer 1

You could filter elements which match in a new array and just return the length of this new array

var j_arry = ["class:1","division:a","class:5","class:3","division:b","division:c","division:d","class:10"];
var res = j_arry.filter(x => x.includes("class"));
var key = res.map(x => x.split(":")[1]);
console.log("Class coming " + res.length + " , at key " + key.join(","));
console.log("new array = ", res);