CODEWITHSUNDEEP
javascriptarrays
Matthew Starkey
Matthew Starkey

Reputation: 757

Display number if each item in JavaScript array

I am trying to display the contents of an array in a more readable way, this is the array:

["malevolent", "pariah", "judicious", "pariah", "judicious"]

I'm simply adding that array to an HTML element to display it, but I want to display it like this:

malevolent, pariah x 2, judicious x2

How would I do this?

Upvotes: 0

Views: 206

Answers (4)

Satish Sharma
Satish Sharma

Reputation: 9635

try this

      var arr = new Array("malevolent", "pariah", "judicious", "pariah", "judicious");

    var new_arr1 = new Array(); // for containing distinct values like pariah
    var new_arr2 = new Array(); // for containing distinct values count like 2 for pariah

   // both will be on same index in new_arr1 and new_arr2

    for(var i=0; i<arr.length; i++)
    {
          // fetch every value of arr

        var indx = $.inArray(arr[i], new_arr1); // check value is exists in new_arr1 and get index

        if(indx > -1) // values exists in new_arr1
        {
             var v = new_arr2[indx]+1; // increment the previous count +1
             new_arr2[indx] = v; // update it on the index of new_arr2
        }
        else         
        {
           // if value not in new_arr1 means the value comes first time
            var l = new_arr1.length;
            new_arr1[l] = arr[i]; // insert value in new_arr1
            new_arr2[l] =  1;         // initate count 1 for the same index of new value in new_arr2 
        }
    }


// now new_arr1 will contains the distinct values
// and new_arr2 contains the count for distinct values 
// eg new_arr1[0] = 'malevolent';
//    new_arr2[0] = 1;

//    new_arr1[1] = 'pariah';
//    new_arr2[1] = 2;


//  now you can fetch distinct values and their count like given below
    for(var i=0; i<new_arr1.length; i++)
    {
       var str = new_arr1[i]+" X "+new_arr2[i];
       alert(str);
    }

See FIDDLE

Upvotes: -1

Grmpfhmbl
Grmpfhmbl

Reputation: 1147

Felix Kling provided a Link to an answer on how to count your elements. I just shamelessly use the reduce method described there and then just iterate over the object to build a string.

var a = ["malevolent", "pariah", "judicious", "pariah", "judicious"].reduce(function (acc, curr) {
    if (typeof acc[curr] == 'undefined') {
        acc[curr] = 1;
    } else {
        acc[curr] += 1;
    }

    return acc;
}, {});

var out = "";

for (var k in a) {
    out += k + " x " + a[k] + "; ";
}

console.log(out);

Upvotes: 0

Jay
Jay

Reputation: 2141

It's quite simple actually:

var myArray = new Array("a", "b", "c", "b", "a");
var newObject = {};
// Iterate over the array
for(var i = 0; i < myArray.length; i++){
    // If the new object already contains the key (e.g. a, b, or c), increment value by one
    if(myArray[i] in newObject){
        newObject[myArray[i]]++;   
    } else {
        // Otherwise add a key (e.g. a, b, or c) to the object and assign 1 to it (first occurence)
        newObject[myArray[i]] = 1;   
    }
}
// Write the resulting object to console
window.console && console.log(newObject);

newObject contains a list of keys (a,b,c) and values (number of occurrences of each key). You can than use that data to output it in any format you like, but that's left up to you as an excercise.

Upvotes: 1

Dharmang
Dharmang

Reputation: 3028

You can try the following:

var myArray = ["malevolent", "pariah", "judicious", "pariah", "judicious"];
var resultArray = [];
var countArray = [];

for(index in myArray) {
    var element = myArray[index];
    var isInArray = resultArray.indexOf(element);
    if(isInArray !== -1) {
        var tmpCnt = countArray[isInArray];
        tmpCnt++;
        countArray[isInArray] = tmpCnt;
    } else {
        resultArray.push(element);
        countArray.push(1);
    }
}
console.log(resultArray);
console.log(countArray);

Upvotes: 1

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