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How can I count the array depending on the value.. I have an array with this value..

var myArr = new Array(3);
myArr[0] = "a";
myArr[1] = "a";
myArr[2] = "b";

I need to count the array depending on the value

Array with Value A is 2 Array with value B is 1

Thanks!


var myArr = new Array(3);
myArr[0] = "a";
myArr[1] = "a";
myArr[2] = "b";


function count(array, value) {
  var counter = 0;
  for(var i=0;i<array.length;i++) {
    if (array[i] === value) counter++;
  }
  return counter;
}

var result = count(myArr, "a");
alert(result);

If you're interested in a built-in function... you could always add your own.

Array.prototype.count = function(value) {
  var counter = 0;
  for(var i=0;i<this.length;i++) {
    if (this[i] === value) counter++;
  }
  return counter;
};

Then you could use it like this.

var result = myArr.count("a");
alert(result);

Javascript Arrays: How to count poperty values (including unique , The array we are going to count property-values from. Now we can use the map method. WHAT IS THE MAP METHOD? Well, it's something  Well, it’s something that creates a new array out of the existing array. As an example, if we have an array like: Now we have an array of surnames. We can count at this point but the amount of values…


Oh well, beaten to the punch, but here's my version.

var myArr = new Array(3);
myArr[0] = "a";
myArr[1] = "a";
myArr[2] = "b"

getCountFromVal( 'a', myArr );

function getCountFromVal( val, arr )
{
    var total =  arr.length;
    var matches = 0;

    for( var i = 0; i < total; i++ )
    {
        if( arr[i] === val )
        {
            matches++;
        }
    }

    console.log(matches);
    return matches;
}

Counting the occurrences / frequency of array elements, In Javascript, I'm trying to take an initial array of number values and count the elements inside it. Ideally, the result would be two new arrays, the first specifying​  array .length = number. Technical Details. A Number, representing the number of elements in the array object. JavaScript Version: JavaScript Tutorial: JavaScript Arrays. JavaScript Array Reference. If you want to report an error, or if you want to make a suggestion, do not hesitate to send us an e-mail: support@w3schools.com.


Live Demo: http://jsfiddle.net/CLjyj/1/

var myArr = new Array(3);
myArr[0] = "a";
myArr[1] = "a";
myArr[2] = "b";

function getNum(aVal)
{
    num=0;
    for(i=0;i<myArr.length;i++)
    {
        if(myArr[i]==aVal)
            num++;
    }
    return num;
}

alert(getNum('a')); //here is the use

How to count object in array - JavaScript, I had an Array like this storage: [ { data: '1', status: '0' }, { data: '2', How to count there is only six data that have status: 0 on javascript? var actualProduct = storage.reduce((value, {status}) => { status == 0 return counter }). The value is an unsigned, 32-bit integer that is always numerically greater than the highest index in the array. The length property of an object which is an instance of type Array sets or returns the number of elements in that array.


I would use Array.filter

  var arr = ['a', 'b', 'b']
  arr.filter(val => val === 'b').length // 2

Array.length, Description. JavaScript array length property returns an unsigned, 32-bit integer that specifies the number of elements in an array. Return Value. Returns the  An array can hold many values under a single name, and you can access the values by referring to an index number. Creating an Array Using an array literal is the easiest way to create a JavaScript Array.


Everyone's already given the obvious function, so I'm going to try and make another solution:

var myArr = [];
myArr[0] = "a";
myArr[1] = "a";
myArr[2] = "b";

function count(arr, value){
    var tempArr = arr.join('').split(''), //Creates a copy instead of a reference
        matches = 0,
        foundIndex = tempArr.indexOf(value); //Find the index of the value's first occurence
    while(foundIndex !== -1){
        tempArr.splice(foundIndex, 1); //Remove that value so you can find the next
        foundIndex = tempArr.indexOf(value);
        matches++;
    }
    return matches;
}

//Call it this way
document.write(count(myArr, 'b'));

Demo

JavaScript - Array length Property, To be precise, it is actually not the count of values in the array, but the greatest numeric index plus one. For instance, a single element with a  The find() method returns the value of the first element in an array that pass a test (provided as a function). If it finds an array element where the function returns a true value, find() returns the value of that array element (and does not check the remaining values) Otherwise it returns undefined


Arrays, In this short post, we will explore JavaScript's super useful Array.find method to help find When you need to find/return multiple values, reach for filter() instead. name: "oak", count: 2 } ]; const result = trees.find(tree => tree.name === "oak");​  How to count duplicate value in an array in javascript. 635. way how to count occurrences with same value in array. How to count duplicate value in an array


Using the Array.find Method in JavaScript ← Alligator.io, learn how to count the number of unique items in a JavaScript array. a little bit naive since we overwrite a given key/value pair for the seen  The function example above will generate an object consists of elements of the array input as the object property and the array of index(es) where each was found as the value (of the object property).


How to Count Unique Items in JavaScript Arrays, echo count($my_array);. In JavaScript, the way to get the size of an array is to use the length property, like this: alert  The includes () method determines whether an array contains a specified element. This method returns true if the array contains the element, and false if not. Note: The includes () method is case sensitive. Browser Support. array .includes ( element, start) Parameter Values. Required. The element to search for.