Introduction to Boolean type analysis based on JavaScript data type _ basics

Today we're talking about a Boolean type in a data type that returns True and false two literals, and it needs to be noted that the literal value is case-sensitive, meaning that all but the lowercase are just identifiers.

The following are mainly about the various data types and corresponding transformation rules:

Value with value converted to true for data type conversion to False

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Boolean true False

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

Number any non 0 digit value 0 and Nan

Object any objects Null

Undefined not suitable for Undefined

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These conversion rules are important to understand that a Process control statement, such as an if statement, automatically performs a corresponding Boolean transformation, see the following code:

Copy Code code as follows:

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