Count instances of string in an array

Question

I have an array in jQuery, and I need to count the number of "true" strings in that array, and then make the "numOfTrue" variable equal the number of true strings. So in the below array, there are 2 "true" strings, so numOfTrue would be equal to 2.

var numOfTrue;
var Answers = [ "true", "false", "false", "true", "false" ];

I'm not sure how to do a loop through the array in jQuery to count the strings. Or is a loop even necessary?

The number of true strings could change from anywhere between 1 to 5.

Answer 1

You don't need jQuery for this.. a simple for loop like below would do the trick,

var numOfTrue = 0;
var Answers = [ "true", "false", "false", "true", "false" ];

for (var i = 0; i < Answers.length; i++) {
    if (Answers[i] === "true") { //increment if true
      numOfTrue++; 
    }
}

or even without a loop, DEMO

Answers.toString().match(/true/g).length

Answer 2

Using a basic, old-fashioned loop:

var numOfTrue = 0;
for(var i=0;i<Answers.length;i++){
    if(Answers[i] === "true")
       numOfTrue++;
}

or, a reduce

var numOfTrue = Answers.reduce((acc,curr) => {
    if(curr === "true")
       acc++;
    return acc;
},0);

or a filter

var numOfTrue = Answers.filter(x => x === "true").length;