Node.js Tutorial - Node.js Array Functions

push and pop

The push and pop functions let you add and remove items to the end of an array, respectively:


var nums = [ 1, 1, 2, 3, 5, 8 ];
nums.push(13);
console.log(nums);
nums.pop();
console.log(nums);

The code above generates the following result.

unshift and shift

To insert or delete items from the front of an array, use unshift or shift , respectively:


var nums = [ 1, 2, 3, 5, 8 ];
nums.unshift(1);
console.log(nums);
nums.shift();
console.log(nums);

join

The array function join returns a string from the array:


var nums = [ 1, 1, 2, 3, 5, 8 ];
var s = nums.join(", ");
console.log(s);

The code above generates the following result.

Sort

You can sort arrays using the sort function, which can be used with the built-in sorting function:


var nums = [ 3, 1, 8, 5, 2, 1];
nums.sort();
console.log(nums);

The code above generates the following result.

We can provide your own sorting function as a parameter:


var names = [ 'CSS', 'HTML', 'Java', 'SQL', 'CSS3', 'HTML5'];
names.sort();/*  w w w .  j a  va  2 s  . co m*/
console.log(names);
names.sort(function (a, b) {
         var a1 = a.toLowerCase(), b1 = b.toLowerCase();
         if (a1 < b1) return 1;
         if (a1 > b1) return -1;
         return 0;
});
console.log(names);

The code above generates the following result.

Loop

To iterate over items in arrays, we can use the for loop or forEach function


[ 'CSS', 'HTML', 'CSS3', 'HTML5', 'Javascript', 'SQL'].forEach( function  (value) {
   console.log(value);
});

The code above generates the following result.