JavaScript data type Boolean type

Today we are talking about a Boolean type in the data type, which returns two literal values ​​of true and false. It should be noted that the 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:

The data type is converted into a true value and converted into a false value

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Boolean true false

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

Any non-zero digital value 0 and nan

Object 　　　 Any object 　　 null

Undefined　　 Not applicable undefined

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

var msg="Hello World";

if(msg){

alert("Valus is true" );
}