Introduction to Boolean type analysis based on JavaScript data types_Basic knowledge

Today we are talking about a Boolean type among data types, which returns two literal values ​​of true and false. It should be noted that literal values ​​are case-sensitive, that is, except for lowercase, everything else is just an identifier.

The following mainly talks about various data types and corresponding conversion rules:

Data type Value converted to true Value converted to false

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Boolean true true

String　　　Any non-empty string　　　""(empty string)

Number Any non-zero numeric value 0 and Nan

Object Any object null

Undefined　　Not applicable　　　　　

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These conversion rules are very important for understanding flow control statements (such as if statements) and automatically performing corresponding Boolean conversions. Please see the following code:

Copy code The code is as follows:

var msg="Hello World";
if(msg){
alert("Valus is true"); }