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Prototype Number object learning_prototype

WBOY
WBOYOriginal
2016-05-16 18:49:531605browse
Copy code The code is as follows:

Object.extend(Number.prototype, (function() {

//Return the hexadecimal color A value
function succ() {
return this 1;
}

//Continuously perform an operation
function times(iterator, context) {
$R (0, this, true).each(iterator, context);
return this;
}

//Return a fixed-length string, padded with 0 in front
function toPaddedString(length , radix) {
var string = this.toString(radix || 10);
return '0'.times(length - string.length) string;
}

function toJSON () {
return isFinite(this) ? this.toString() : 'null';
}

function abs() {
return Math.abs(this);
}

function round() {
return Math.round(this);
}

function ceil() {
return Math.ceil(this);
}

function floor() {
return Math.floor(this);
}

return {
toColorPart: toColorPart,
succ: succ,
times: times,
toPaddedString: toPaddedString,
toJSON: toJSON,
abs: abs,
round: round,
ceil: ceil,
floor: floor
};
})());


Here are a few prototype extension methods.
times method:
Look at the example



Copy the code
The code is as follows: var s = ''; (5).times(function(n) { s = n; });
alert(s);
// -> '01234'

//Function prototype: times(iterator) -> Number, basically executing the iterator method N times continuously, and the first parameter passed to iterator is 0~N-1

/ *
Pay attention to the writing method when calling the method: 5 must be added in parentheses, otherwise writing 5.times directly will cause syntax errors. Because the dot after 5 will be parsed as a decimal point, and a decimal point followed by a string will have a syntax error.
You can also write it in another way: 5['times'](function(n) { s = n; });
In fact, the relationship between 5 and Number here is equivalent to int and Integer in C# Almost the same
*/




toJSON method:

The isFinite(number) in this method is a global method provided by JavaScript:

If number is not NaN, negative infinity or positive infinity, then the isFinite method will return true. In these three cases, the function returns false.

I won’t explain the rest of the method, it’s too simple, just show a few examples:

Copy code

The code is as follows:(5).succ() // -> 6 $A($R(1, 5)).join(' ')
// -> '12345'

(128).toColorPart()
// -> '80'
(10).toColorPart()
// -> '0a'

(13).toPaddedString(4); // -> '0013'
(13).toPaddedString(2); // -> '13 '
(13).toPaddedString(1); // -> '13'
(13).toPaddedString(4, 16) // -> '000d'
(13).toPaddedString (4, 2); // -> '1101'



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