Date Object
The Date object is used to work with dates and times.
Date objects are created with new Date().
There are four ways of instantiating a date:
var d = new Date();
var d = new Date(milliseconds);
var d = new Date(dateString);
var d = new Date(year, month, day, hours, minutes, seconds, milliseconds);
var d = new Date(milliseconds);
var d = new Date(dateString);
var d = new Date(year, month, day, hours, minutes, seconds, milliseconds);
Date Object Properties
| Property | Description |
|---|---|
| constructor | Returns the function that created the Date object's prototype |
| prototype | Allows you to add properties and methods to an object |
Date Object Methods
| Method | Description |
|---|---|
| getDate() | Returns the day of the month (from 1-31) |
| getDay() | Returns the day of the week (from 0-6) |
| getFullYear() | Returns the year (four digits) |
| getHours() | Returns the hour (from 0-23) |
| getMilliseconds() | Returns the milliseconds (from 0-999) |
| getMinutes() | Returns the minutes (from 0-59) |
| getMonth() | Returns the month (from 0-11) |
| getSeconds() | Returns the seconds (from 0-59) |
| getTime() | Returns the number of milliseconds since midnight Jan 1, 1970 |
| getTimezoneOffset() | Returns the time difference between GMT and local time, in minutes |
| getUTCDate() | Returns the day of the month, according to universal time (from 1-31) |
| getUTCDay() | Returns the day of the week, according to universal time (from 0-6) |
| getUTCFullYear() | Returns the year, according to universal time (four digits) |
| getUTCHours() | Returns the hour, according to universal time (from 0-23) |
| getUTCMilliseconds() | Returns the milliseconds, according to universal time (from 0-999) |
| getUTCMinutes() | Returns the minutes, according to universal time (from 0-59) |
| getUTCMonth() | Returns the month, according to universal time (from 0-11) |
| getUTCSeconds() | Returns the seconds, according to universal time (from 0-59) |
| getYear() | Deprecated. Use the getFullYear() method instead |
| parse() | Parses a date string and returns the number of milliseconds since midnight of January 1, 1970 |
| setDate() | Sets the day of the month (from 1-31) |
| setFullYear() | Sets the year (four digits) |
| setHours() | Sets the hour (from 0-23) |
| setMilliseconds() | Sets the milliseconds (from 0-999) |
| setMinutes() | Set the minutes (from 0-59) |
| setMonth() | Sets the month (from 0-11) |
| setSeconds() | Sets the seconds (from 0-59) |
| setTime() | Sets a date and time by adding or subtracting a specified number of milliseconds to/from midnight January 1, 1970 |
| setUTCDate() | Sets the day of the month, according to universal time (from 1-31) |
| setUTCFullYear() | Sets the year, according to universal time (four digits) |
| setUTCHours() | Sets the hour, according to universal time (from 0-23) |
| setUTCMilliseconds() | Sets the milliseconds, according to universal time (from 0-999) |
| setUTCMinutes() | Set the minutes, according to universal time (from 0-59) |
| setUTCMonth() | Sets the month, according to universal time (from 0-11) |
| setUTCSeconds() | Set the seconds, according to universal time (from 0-59) |
| setYear() | Deprecated. Use the setFullYear() method instead |
| toDateString() | Converts the date portion of a Date object into a readable string |
| toGMTString() | Deprecated. Use the toUTCString() method instead |
| toLocaleDateString() | Returns the date portion of a Date object as a string, using locale conventions |
| toLocaleTimeString() | Returns the time portion of a Date object as a string, using locale conventions |
| toLocaleString() | Converts a Date object to a string, using locale conventions |
| toString() | Converts a Date object to a string |
| toTimeString() | Converts the time portion of a Date object to a string |
| toUTCString() | Converts a Date object to a string, according to universal time |
| UTC() | Returns the number of milliseconds in a date string since midnight of January 1, 1970, according to universal time |
| valueOf() | Returns the primitive value of a Date object |
Math Object
The Math object allows you to perform mathematical tasks.
Math is not a constructor. All properties/methods of Math can be called by using Math as an object, without creating it.
Syntax
var x = Math.PI; // Returns PI
var y = Math.sqrt(16); // Returns the square root of 16
var y = Math.sqrt(16); // Returns the square root of 16
Math Object Properties
| Property | Description |
|---|---|
| E | Returns Euler's number (approx. 2.718) |
| LN2 | Returns the natural logarithm of 2 (approx. 0.693) |
| LN10 | Returns the natural logarithm of 10 (approx. 2.302) |
| LOG2E | Returns the base-2 logarithm of E (approx. 1.442) |
| LOG10E | Returns the base-10 logarithm of E (approx. 0.434) |
| PI | Returns PI (approx. 3.14159) |
| SQRT1_2 | Returns the square root of 1/2 (approx. 0.707) |
| SQRT2 | Returns the square root of 2 (approx. 1.414) |
Math Object Methods
| Method | Description |
|---|---|
| abs(x) | Returns the absolute value of x |
| acos(x) | Returns the arccosine of x, in radians |
| asin(x) | Returns the arcsine of x, in radians |
| atan(x) | Returns the arctangent of x as a numeric value between -PI/2 and PI/2 radians |
| atan2(y,x) | Returns the arctangent of the quotient of its arguments |
| ceil(x) | Returns x, rounded upwards to the nearest integer |
| cos(x) | Returns the cosine of x (x is in radians) |
| exp(x) | Returns the value of Ex |
| floor(x) | Returns x, rounded downwards to the nearest integer |
| log(x) | Returns the natural logarithm (base E) of x |
| max(x,y,z,...,n) | Returns the number with the highest value |
| min(x,y,z,...,n) | Returns the number with the lowest value |
| pow(x,y) | Returns the value of x to the power of y |
| random() | Returns a random number between 0 and 1 |
| round(x) | Rounds x to the nearest integer |
| sin(x) | Returns the sine of x (x is in radians) |
| sqrt(x) | Returns the square root of x |
| tan(x) | Returns the tangent of an angle |
Number Object
The Number object is an object wrapper for primitive numeric values.
Number objects are created with new Number().
Syntax
var num = new Number(value);
Note: If the value parameter cannot be converted into a number, it returns NaN (Not-a-Number).
Number Object Properties
| Property | Description |
|---|---|
| constructor | Returns the function that created the Number object's prototype |
| MAX_VALUE | Returns the largest number possible in JavaScript |
| MIN_VALUE | Returns the smallest number possible in JavaScript |
| NEGATIVE_INFINITY | Represents negative infinity (returned on overflow) |
| POSITIVE_INFINITY | Represents infinity (returned on overflow) |
| prototype | Allows you to add properties and methods to an object |
Number Object Methods
| Method | Description |
|---|---|
| toExponential(x) | Converts a number into an exponential notation |
| toFixed(x) | Formats a number with x numbers of digits after the decimal point |
| toPrecision(x) | Formats a number to x length |
| toString() | Converts a Number object to a string |
| valueOf() | Returns the primitive value of a Number object |
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