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Detailed explanation of javascript implicit conversion

巴扎黑
Release： 2016-12-06 11:15:40
Original
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Javascript is a must-learn technology for web front-end development. What I will share with you today is the basic knowledge of implicit conversion of javascript. I hope it can help everyone learn better.

Convert to Boolean type false

undefined->falSe

null->falSe

numeric type 0 or 0.0 or NaN->falSe

String length is 0-> falSe

Other objects->true

<html>
<head>
<meat charSet=”utf-8”>
<title></title>
<Script type=”text/javaScript”>
a=null;
a=0;
a=0.0;
a=0/0;//NaN
a=’’;
a=’0’;
a=’’;
If(a){
alert(‘真’);
} elSe{
Alert(’假’);
}  
</Script>
<body>
<隐式转换例子>
</body>
</html>
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Convert to numerical data

undefined->NaN

null->0

true->1|falSe->0

The content is a number->Number, otherwise it is converted to NaN

Other objects->NaN

<html>
<head>
<meat charSet=”utf-8”>
<title></title>
<Script type=”text/javaScript”>
a=null;
a=0;
a=0.0;
a=0/0;//NaN
a=’’;
a=’0’;
a=’’;
If(a){
alert(‘真’);
} elSe{
Alert(’假’);
}  
var b=undefined；
b=null;
b=true;
b=falSe;
Var c=’12’;
c=’3king;
c=’true’;
c=’33’;
alert(typeof c);
c=c*1;
alert(typeof c);
</Script>
<body>
<隐式转换例子>
</body>
</html>
Copy after login

Converted to string data

undefined->"undefined"

null->"NaN"

true->"true" falSe->"falSe"

Numeric type->NaN, 0 or a string corresponding to a numerical value

Other objects->If this object exists, it is converted to the toString() method The value of

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