get maximum length of JavaScript array element

One-liner for you:

 Math.max.apply(Math, $.map(array, function (el) { return el.length }));

Working example: http://jsfiddle.net/5SDBx/

You can do it without jQuery in newer browsers (or even older browsers with a compatibility implementation of Array.prototype.map) too:

Math.max.apply(Math, array.map(function (el) { return el.length }));

A new answer to an old question: in ES6 you can do even shorter:

Math.max(...array.map(el => el.length));

In such cases, there is a very useful function. Array.reduce

['a', 'abcde', 'ab'].reduce((r,s) => r.length > s.length ? r : s, 0);

This will return the longest string. To get its length, use:

['a', 'abcde', 'ab'].reduce((m,x) => x.length > m ? x.length : m, 0);

One (possibly rubbish) way of doing that, without using Jquery:

var myarray = ['a','abcde','ab'];
var maxlen = 0;
for (i=0; i<myarray.length; i++) {
  if (myarray[i].length>maxlen) {
    maxlen = myarray[i].length;
  }
}

By using Array.prototype.reduce(), you can elegantly perform a Math.max() calculation for each item in the array. It does not matter whether the items in the array are string or sub-arrays (2D array, matrix, etc.), this will work because String and Array both have a prototype.length() function.

I also added a check for integer values per your comment above.

function arrayItemMax(arr) {
    return arr.reduce(function (result, val) {
        return Math.max(result, !isNaN(val) ? parseInt(val) : val.length);
    }, 0);
}

function print(text) {
  document.getElementsByTagName('body')[0].innerHTML += text + '<br />';
}

print(arrayItemMax(['a', 'abcde', 'ab'])); // 5
print(arrayItemMax([1, 5, 2]));            // 5
print(arrayItemMax(['1', '5', '2']));      // 5

One liner:

function(a){return a.reduce(function(r,v){return Math.max(r,!isNaN(v)?parseInt(v):v.length);},0);}

You could use jQuery's each() to iterate a little nicer.

var maxLength = 0;

$.each(array, function(i, item) {
   maxLength = Math.max(maxLength, item.length);
});

Or plain ol' JavaScript...

var maxLength = 0;

for (var i = 0, length = array.length; i < length; i++) {
   maxLength = Math.max(maxLength, array[i].length);
};

There are several ways to do that.

I would iterate through all the array elements and store the longest element in a local variable. You get the longest element by comparing the first array element with the second, then storing the longer one. Then go on and compare each element with the longest one so far.

You just need one loop to do that.

You can create own your code. Follow this ->

Array.prototype.count = function(){  return this.length; }

then use

arr = [ "erhan",1,"sonmez",2 ];
arrCount = arr.count();