Prototype JavaScript framework - Number

round

2007-11-06T03:08:00Z

round() -> Number

Rounds the number to the nearest integer.

An instance-method version of Math.round.

Examples

Math.round(4.5) //-> 5
(4.5).round()   //-> 5
(4.49).round()  //-> 4
(-4.5).round()  //-> -4

floor

2007-11-06T03:06:00Z

floor() -> Number

Returns the largest integer less than or equal to the number.

An instance-method version of Math.floor.

Examples

Math.floor(4.6) //-> 4
(4.6).floor()   //-> 4
(-4.1).floor()  //-> -5

ceil

2007-11-06T03:03:00Z

ceil() -> Number

Returns the smallest integer greater than or equal to the number.

An instance-method version of Math.ceil.

Examples

Math.ceil(4.1) //-> 5
(4.1).ceil()   //-> 5
(-4.1).ceil()  //-> -4

abs

2007-11-06T02:58:00Z

abs() -> Number

Returns the absolute value of the number.

An instance-method version of Math.abs.

Examples

Math.abs(-5) //-> 5
(-5).abs()   //-> 5
(5).abs()    //-> 5

toJSON

2007-03-10T00:44:00Z

toJSON() -> String

Returns a JSON string.

Example


(45).toJSON();
//-> '45'

toPaddedString

2007-03-09T19:03:00Z

toPaddedString(length[, radix]) -> String

Converts the number into a string padded with 0s so that the string’s length is at least equal to length. Takes an optional radix argument which specifies the base to use for conversion.

Examples


(13).toPaddedString(4);
// -> '0013'

(13).toPaddedString(2);
// -> '13'

(13).toPaddedString(1);
// -> '13'

(13).toPaddedString(4, 16)
// -> '000d'

(13).toPaddedString(4, 2);
// -> '1101'

Number

2006-12-05T21:47:00Z

Prototype extends native JavaScript numbers in order to provide:

ObjectRange compatibility, through Number#succ.
Ruby-like numerical loops with Number#times.
Simple utility methods such as Number#toColorPart and Number#toPaddedString.

What becomes possible


$R(1, 10).each(function(index) {
  // This gets invoked with index from 1 to 10, inclusive
});

(5).times(function(n) {
  // This gets invoked with index from 0 to 5, *exclusive*
  // The parentheses are due to JS syntax, if we did not use a literal, they'd be superfluous
});

(128).toColorPart()
// -> '80'

(10).toColorPart()
// -> '0a'

'#' + [128, 10, 16].invoke('toColorPart').join('')
// -> '#800a10'

succ

2006-11-18T18:00:00Z

succ() -> Number

Returns the successor of the current Number, as defined by current + 1. Used to make numbers compatible with ObjectRange.

Examples


(5).succ()
// -> 6

$A($R(1, 5)).join('')
// -> '12345'

times

2006-11-18T18:00:00Z

times(iterator) -> Number

Encapsulates a regular [0..n[ loop, Ruby-style.

The callback function is invoked with a single argument, ranging from 0 to the number, exclusive.

Examples


var s = '';
(5).times(function(n) {
  s += n;
});

s
// -> '01234'

toColorPart

2006-11-18T17:59:00Z

toColorPart() -> String

Produces a 2-digit hexadecimal representation of the number (which is therefore assumed to be in the [0..255] range). Useful for composing CSS color strings.

Examples


128.toColorPart()
// -> '70'

10.toColorPart()
// -> '0a'

'#' + [128, 10, 16].invoke('toColorPart').join('')
// -> '#800a10'