THA6

THA DAY 6
ARRAY ASSIGNMENT

1. Write a JavaScript function to check whether an `input` is an array or
not
Test Data :
console.log(is_array('w3resource'));
console.log(is_array([1, 2, 4, 0]));
false
True

CODE
var is_array = function(input) {
if (toString.call(input) === "[object Array]")
return true;
return false;
};
console.log(is_array('w3resource'));
console.log(is_array([1, 2, 4, 0]));


2.Write a JavaScript function to clone an array
Test Data :
console.log(array_Clone([1, 2, 4, 0]));
console.log(array_Clone([1, 2, [4, 0]]));
[1, 2, 4, 0]
[1, 2, [4, 0]]

CODE
var array_Clone = function(arra1) {
return arra1.slice(0);
};
console.log(array_Clone([1, 2, 4, 0]));
console.log(array_Clone([1, 2, [4, 0]]));

3.Write a JavaScript function to get the first element of an array. Passing a
parameter 'n' will return the first 'n' elements of the array.
Test Data :
console.log(first([7, 9, 0, -2]));
console.log(first([],3));
console.log(first([7, 9, 0, -2],3));
console.log(first([7, 9, 0, -2],6));console.log(first([7, 9, 0, -2],-3));
CODE

var first = function(array, n) {
if (array == null)
return void 0;
if (n == null)
return array[0];
if (n < 0)
return [];
return array.slice(0, n);
};
console.log(first([7, 9, 0, -2]));
console.log(first([],3));
console.log(first([7, 9, 0, -2],3));
console.log(first([7, 9, 0, -2],6));
console.log(first([7, 9, 0, -2],-3));

4. Write a simple JavaScript program to join all elements of the following array
into a string.
Sample array : myColor = ["Red", "Green", "White", "Black"];

CODE
myColor = ["Red", "Green", "White", "Black"];
console.log(myColor.toString());
console.log(myColor.join());
console.log(myColor.join('+'));

5. Write a JavaScript program to find the most frequent item of an array
Sample array : var arr1=[3, 'a', 'a', 'a', 2, 3, 'a', 3, 'a', 2, 4, 9, 3];
CODE

var arr1=[3, 'a', 'a', 'a', 2, 3, 'a', 3, 'a', 2, 4, 9, 3];
var mf = 1;
var m = 0;
var item;
for (var i=0; i<arr1.length; i++)
{
for (var j=i; j<arr1.length; j++)
{if (arr1[i] == arr1[j])
m++;
if (mf<m)
{
mf=m;
item = arr1[i];
}
}
m=0;
}
console.log(item+" ( " +mf +" times ) ")