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>
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>
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