JS内置函数应用.docx

JS内置函数应用.docx

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JS内置函数应用

1extend

DOCTYPEhtml>

String.prototype.reverse=function（）{

returnArray.prototype.reverse.apply（this.split（''））.join（''）;

}

console.log（'maizi'.reverse（））;

console.log（'king'.reverse（））;

//检测方法是否存在，不存在则扩展

if（!

Array.prototype.inArray）{

Array.prototype.inArray=function（needle）{

for（vari=0,len=this.length;i

if（this[i]==needle）{

returntrue;

}

}

returnfalse;

}

}

vararr=['a','b','c','d'];

console.log（arr.inArray（'b'））;

console.log（arr.inArray（"C"））;

functionPerson（）{

this.mouth=true;

}

varp1=newPerson（）;

varp2=newPerson（）;

Person.prototype.say=function（）{

return'hello';

}

console.log（p1.say（））;

console.log（p2.say（））;

console.log（p1.constructor）;

console.log（p1.constructor.prototype.constructor）;

console.log（p1.constructor.prototype.mouth）;

Person.prototype={

hair:

true,

face:

true

};

console.log（typeofp1.hair）;

console.log（p1.say（））;

console.log（typeofp1.__proto__.say）;

console.log（typeofp1.__proto__.hair）;

varp3=newPerson（）;

console.log（typeofp3.__proto__.say）;

console.log（typeofp3.__proto__.hair）;

console.log（typeofp3.__proto__.face）;

console.log（p3.constructor）;

console.log（p1.constructor）;

console.log（typeofp3.constructor.prototype.hair）;

console.log（typeofp1.constructor.prototype.hair）;

Person.prototype={

'hair':

true,

face:

true

};

Person.prototype.constructor=Person;

varp4=newPerson（）;

console.log（p4.constructor）;

console.log（typeofp4.constructor.prototype.hair）;

2重置constructor

DOCTYPEhtml>

functionShape（）{

this.name='shape';

this.toString=function（）{

returnthis.name;

}

}

functionTwoDShape（）{

this.name='2Dshape';

}

functionTriangle（side,height）{

this.name='triangle';

this.side=side;

this.height=height;

this.getArea=function（）{

returnthis.side*this.height/2;

}

}

TwoDShape.prototype=newShape（）;

Triangle.prototype=newTwoDShape（）;

//重置constructor属性

TwoDShape.prototype.constructor=TwoDShape;

Triangle.prototype.constructor=Triangle;

varmyTriangle=newTriangle（5,10）;

console.log（myTriangle.getArea（））;

console.log（myTriangle.toString（））;

console.log（myTriangle.constructor）;

console.log（myTriangleinstanceofTriangle）;

console.log（myTriangleinstanceofTwoDShape）;

console.log（myTriangleinstanceofShape）;

console.log（Shape.prototype.isPrototypeOf（myTriangle））;

console.log（TwoDShape.prototype.isPrototypeOf（myTriangle））;

console.log（Triangle.prototype.isPrototypeOf（myTriangle））;

console.log（Object.prototype.isPrototypeOf（myTriangle））;

console.log（String.prototype.isPrototypeOf（myTriangle））;

vartd=newTwoDShape（）;

console.log（td.constructor）;

console.log（td.toString（））;

vars=newShape（）;

console.log（s.constructor）;

console.log（s.toString（））;

3Shape

DOCTYPEhtml>

//functionShape（）{

//this.name='shape';

//}

functionShape（）{};

Shape.prototype.name='shape';

Shape.prototype.toString=function（）{

returnthis.name;

}

functionTwoDShape（）{};

TwoDShape.prototype=newShape（）;

TwoDShape.prototype.constructor=TwoDShape;

TwoDShape.prototype.name='2DShape';

functionTriangle（side,height）{

this.side=side;

this.height=height;

}

Triangle.prototype=newTwoDShape（）;

Triangle.prototype.constructor=Triangle;

Triangle.prototype.name='triangle';

Triangle.prototype.getArea=function（）{

returnthis.side*this.height/2;

}

varmyTriangle=newTriangle（5,10）;

console.log（myTriangle.getArea（））;

console.log（myTriangle.toString（））;

console.log（myTriangle.hasOwnProperty（'side'））;

console.log（myTriangle.hasOwnProperty（'name'））;

console.log（myTriangleinstanceofTriangle）;

console.log（myTriangleinstanceofTwoDShape）;

console.log（myTriangleinstanceofShape）;

console.log（Triangle.prototype.isPrototypeOf（myTriangle））;

console.log（TwoDShape.prototype.isPrototypeOf（myTriangle））;

console.log（Shape.prototype.isPrototypeOf（myTriangle））;

console.log（Object.prototype.isPrototypeOf（myTriangle））;

4字符串

DOCTYPEhtml>

functionShape（）{};

Shape.prototype.name='shape';

Shape.prototype.toString=function（）{

returnthis.name;

}

functionTwoDShape（）{};

TwoDShape.prototype=Shape.prototype;

TwoDShape.prototype.constructor=TwoDShape;

TwoDShape.prototype.name='2DShape';

functionTriangle（side,height）{

this.side=side;

this.height=height;

}

Triangle.prototype=TwoDShape.prototype;

Triangle.prototype.constructor=Triangle;

Triangle.prototype.name='triangle';

Triangle.prototype.getArea=function（）{

returnthis.side*this.height/2;

}

varmy=newTriangle（5,10）;

console.log（my.getArea（））;

console.log（my.toString（））;

vars=newShape（）;

console.log（s.name）;

5属性构造

DOCTYPEhtml>

functionShape（）{};

Shape.prototype.name='Shape';

Shape.prototype.toString=function（）{

returnthis.name;

}

functionTwoDShape（）{};

//声明临时构造器

varF=function（）{};

F.prototype=Shape.prototype;

TwoDShape.prototype=newF（）;

TwoDShape.prototype.constructor=TwoDShape;

TwoDShape.prototype.name='2DShape';

functionTriangle（side,height）{

this.side=side;

this.height=height;

}

varF=function（）{};

F.prototype=TwoDShape.prototype;

Triangle.prototype=newF（）;

Triangle.prototype.constructor=Triangle;

Triangle.prototype.name='triangle';

Triangle.prototype.getArea=function（）{

returnthis.side*this.height/2;

}

varmy=newTriangle（5,10）;

console.log（my.getArea（））;

console.log（my.toString（））;

console.log（my.__proto__.__proto__.__proto__.constructor）;

vars=newShape（）;

console.log（s.name）;

6uber

DOCTYPEhtml>

functionShape（）{};

Shape.prototype.name='Shape';

Shape.prototype.toString=function（）{

varresult=[];

if（this.constructor.uber）{

result[result.length]=this.constructor.uber.toString（）;

}

result[result.length]=this.name;

returnresult.join（','）;

};

functionTwoDShape（）{};

varF=function（）{};

F.prototype=Shape.prototype;

TwoDShape.prototype=newF（）;

TwoDShape.prototype.constructor=TwoDShape;

TwoDShape.uber=Shape.prototype;

TwoDShape.prototype.name='2DShape';

functionTriangle（side,height）{

this.side=side;

this.height=height;

}

varF=function（）{};

F.prototype=TwoDShape.prototype;

Triangle.prototype=newF（）;

Triangle.prototype.constructor=Triangle;

Triangle.uber=TwoDShape.prototype;

Triangle.prototype.name='triangle';

Triangle.prototype.getArea=function（）{

returnthis.side*this.height/2;

}

varmy=newTriangle（5,10）;

console.log（my.getArea（））;

console.log（my.toString（））;

vartd=newTwoDShape（）;

console.log（td.toString（））;

7属性继承

DOCTYPEhtml>

functionextend（Child,Parent）{

varF=function（）{};

F.prototype=Parent.prototype;

Child.prototype=newF（）;

Child.prototype.constructor=Child;

Child.uber=Parent.prototype;

}

functionShape（）{};

Shape.prototype.name='Shape';

Shape.prototype.toString=function（）{

varresult=[];

if（this.constructor.uber）{

result[result.length]=this.constructor.uber.toString（）;

}

result[result.length]=this.name;

returnresult.join（','）;

};

functionTwoDShape（）{};

extend（TwoDShape,Shape）;

TwoDShape.prototype.name='2DShape';

functionTriangle（side,height）{

this.side=side;

this.height=height;

}

extend（Triangle,TwoDShape）;

Triangle.prototype.name='triangle';

Triangle.prototype.getArea=function（）{

returnthis.side*this.height/2;

}

varmy=newTriangle（5,10）;

console.log（my.getArea（））;

console.log（my.toString（））;

vartd=newTwoDShape（）;

console.log（td.toString（））;

8元素继承

DOCTYPEhtml>

functionextend（Child,Parent）{

varF=function（）{};

F.prototype=Parent.prototype;

Child.prototype=newF（）;

Child.prototype.constructor=Child;

Child.uber=Parent.prototype;

}

functionextend1（Child,Parent）{

varp=Parent.prototype;

varc=Child.prototype;

for（variinp）{

c[i]=p[i];

}

c.uber=p;

}

varShape=function（）{};

varTwoDShape=function（）{};

Shape.prototype.name='shape';

Shape.prototype.toString=function（）{

returnthis.name;

}

extend（TwoDShape,Shape）;

vartd=ne