A brief analysis of Prototype source code Number part_prototype

There are relatively few methods in the Number part, with a total of 8:

toColorPart: Convert the Number object into a hexadecimal form with two digits
succ: Return the next value of the current Number object, which is the current value Value plus one
times: Use Ruby style to encapsulate a standard [0...n] loop
toPaddedString: Convert the current Number object to a string, if the converted string length is less than length specified value, use 0 to pad the remaining digits on the left
abs: Returns the absolute value of the current Number object.
round: Returns the rounded integer value of the current Number object.
ceil: Returns the smallest integer value greater than or equal to the current Number object.
floor: Returns the largest integer value less than or equal to the current Number object.

One of the important methods is toPaddedString. Number object overrides the toString method:
NumberObject.toString(radix)

参数	描述
radix	可选。规定表示数字的基数，使 2 ~ 36 之间的整数。若省略该参数，则使用基数 10。但是要注意，如果该参数是 10 以外的其他值，则 ECMAScript 标准允许实现返回任意值。

Copy code The code is as follows:

function toPaddedString(length,radix){
var string = this.toString(radix || 10);//Convert the number to the corresponding base first
return '0'.times(length - string.length) string;//The times method is extended in String , repeat a character n times
}

With this method, there is a more useful extension is toColorPart, which can be used for color conversion in CSS:

Copy code The code is as follows:

function toColorPart() {
return this.toPaddedString(2, 16);
}

Since it is CSS color conversion, the number must be in the range of [0-255].

console.log((10).toColorPart());//0a
There is a method succ with the same name as String, which has the same effect. In String, it is incremented according to the character table. Number is based on the order of natural numbers.

Copy code The code is as follows:

function succ() {
return this 1;
}

console.log((10).succ());//11
Starting from this method, let’s create a simple 0-n array

Copy code The code is as follows:

function range(){
var ret = [0];
for(var i = 0; i < this - 1; i ){
ret.push(i.succ());
}
return ret;
}

console.log((10).range());//[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Use this range function temporarily To get the times function:

Copy code The code is as follows:

function times(iterator, context) {
this.range().forEach(iterator, context); //The R() method is used in the source code
return this;
}

Copy code The code is as follows:

var s = '';
(5).times(function(item ){
s = item;
});
console.log(s);//01234

Except for the above methods, the other method is to use Math Static methods are extended to Number objects [The statement is not accurate, I understand...=. =]

Copy code The code is as follows:

function abs() {
return Math .abs(this);
}
function round() {
return Math.round(this);
}
function ceil() {
return Math.ceil(this );
}
function floor() {
return Math.floor(this);
}