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javascriptarrayscount
Rich
Rich

Reputation: 185

Count the occurrence of value in an array

I have an array as below:

values = [["Cat", true], ["Dog", false], ["Cow", false], ["Owl", true]]

Now I want a code in ReactJS to check how many true are there and how many false.

Someone help me.

Upvotes: 0

Views: 96

Answers (6)

Jay
Jay

Reputation: 29

This is not a question about react, but about javascript.

One way to go about that is to write a method that counts all occurences.

values.filter(item => item[1] === true).length

This will filter out only items that are TRUE and return the length of this array. Same can be done for filtering false values, or you can subtract true values from the length of the array if you're sure you only have true and false values throughout.

Upvotes: 1

Soham
Soham

Reputation: 725

Be careful with Truthy & Falsy

let values = [
  ["Cat", true],
  ["Dog", false],
  ["Cow", 1],
  ["Owl", 0],
  ["donkey", 0]
]
let truthy = 0;
let nonTruthy = 0;
let trueCount = 0;
let falseCount = 0;

values.forEach(ele => {
  if (ele[1] === true) trueCount++;
  if (ele[1] === false) falseCount++;
})

values.forEach(ele => {
  ele[1] ? truthy++ : nonTruthy++
})

console.log(trueCount, falseCount) // 1 1 
console.log(truthy, nonTruthy) // 2 3

Upvotes: 2

Rajneesh
Rajneesh

Reputation: 5308

How about making use of flat() then filtering it out:

var values = [["Cat", true], ["Dog", false], ["Cow", false], ["Owl", true]]
var result = values.flat().filter(k=>k==true).length;
console.log(result);

Upvotes: 0

ofekm97
ofekm97

Reputation: 3

I am not really familiar with the values array, but if it keeps its formation you can use this:

let filteredArray = values.filter((val) => val[1] === true).length;

Hope I helped!

Upvotes: 0

grzim
grzim

Reputation: 604

The simplest way to achive it is to use filter

const values = [["Cat", true], ["Dog", false], ["Cow", false], ["Owl", true]];

const trueVals = values.filter(item => item[1]).length;
const falseVals = values - trueVals;

hope it helps!

Upvotes: 0

aturan23
aturan23

Reputation: 5390

Working example:

 const values = [["Cat", true], ["Dog", false], ["Cow", false], ["Owl", true]];
  let counter = 0;
  values.map((item) => {
    if (item[1]) {
      counter++;
    }
  });
  console.log(counter);

Upvotes: 0

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