The Number object
Numbers in JavaScript are
64 bit (8 bytes) floating point numbers.
Syntax for creating Number object
var num = new Number(value)
Properties of Number object
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Properties
|
Description
|
|
constructor
|
Holds the value of constructor function that has
created the object
|
|
MAX VALUE
|
Returns the maximum numerical value possible in
javaScript
|
|
MIN VALUE
|
Returns the minimum numerical value possible in
javaScript
|
|
NEGATIVE INFINITY
|
Represents the value of negative infinity
|
|
POSITIVE INFINITY
|
Represents the value of positive infinity
|
|
prototype
|
Adds properties and methods to the number object
|
Methods of the Number object
|
Method
|
Description
|
|
toExponential(x)
|
Converts number into exponential notation
|
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toFixed(x)
|
Rounds up a number to x digit after the decimal
|
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toPrecision(x)
|
Rounds up a number to a length of x digits
|
|
toString()
|
Returns a string value of the Number object
|
|
valueOf()
|
Returns a primitive value of the Number object
|
Example
<!DOCTYPE html>
<html>
<head>
<title>JavaScript Number Objects</title>
</head>
<body>
<h1>JavaScript Number Objects</h1>
<script>
number = new Number(12.5678);
document.write(number.toExponential() + '<br/>');
document.write(number.toFixed() + '<br/>');
document.write(number.toPrecision(2) + '<br/>');
document.write(number.toString() + '<br/>');
document.write(number.valueOf() + '<br/>');
</script>
</body>
</html>
The Array object
It is
store multiple values in a single variable. It can hold different data type
value in a single slot.
It can be created using
1.
array
constructor
2.
array
literal notation
Using array constructor
Creating
empty array: var new_array= new array();
Creating
array of a given size: var new_array= new array(size);
Creating
array with elements: var new_array= new array(“first element”, “second
Element”);
Using array literal notation
Array
literal notation is a comma separated list of items enclosed by square
brackets.
Creating
empty array: var new_array=[];
Creating
array with elements: var new_array= [“element1”, “element2”];
Properties of array object
|
Properties
|
Description
|
|
constructor
|
Holds the value of constructor
function that has created the object
|
|
length
|
Holds the number of elements in
an array
|
|
prototype
|
Adds properties and methods to
the array object
|
Methods of an array object
|
Properties
|
Description
|
|
concat()
|
Joins two or more arrays and
returns the joined array
|
|
join()
|
Joins all the elements of an
array into a string
|
|
pop()
|
Removes the last element of an
array and return the element
|
|
push()
|
Adds new element as last
element and returns length of the new array
|
|
reverse()
|
Reverses the order of list of element
in an array
|
|
shift()
|
Removes the first element of an
array and returns the element
|
|
slice()
|
Selects a part of an array and
returns that part of new array.
|
|
sort()
|
Sorts the element of an array
|
|
splice()
|
Adds or removes the element of
an array
|
|
toString()
|
Converts an array into a string
and returns the string
|
|
unshift()
|
Adds new elements to an array
and returns the new length
|
|
valueof()
|
Returns the primitive value of
an array object
|
Example
<!DOCTYPE html>
<html>
<head>
<title>JavaScript Array Objects</title>
</head>
<body>
<h1>JavaScript Array Objects</h1>
<script>
array_months = new Array('Jan', 'Feb', 'Mar', 'April', 'May', 'June');
array_num = new Array(1, 2, 3, 4, 5, 6);
document.write('Array 1: '+array_months + '<br/>');
document.write('Array 2: ' + array_num + '<br/>');
document.write('concat two arrays: ' + array_months.concat(array_num) + '<br/>');
document.write('join two arrays: ' + array_months.join(array_num) + '<br/>');
document.write('Array 1 pop out: ' + array_months.pop() + '<br/>');
document.write('Array 2 revers: ' + array_num.reverse() + '<br/>');
document.write('Shifted array 1 : ' + array_months.shift() + '<br/>');
document.write('Sorted array 1: ' + array_months.sort() + '<br/>');
</script>
</body>
</html>
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