What are the rules for converting JS type values ​​into Boolean types?

This time I will bring you the rules for converting JS type values ​​into Boolean types, and what are the precautions for converting JS type values ​​into Boolean types. The following is a practical case, let’s take a look. one time.

Due to the recent written examination, I found a lot of questions about converting other types into Boolean types, so I will summarize it!

1. Convert the

String type to Boolean

1. When the result of conversion j is true

①Any non-empty

string

PS: Blank strings also return true

2. When the conversion result is false

①Empty string

##2. Convert Number type to Boolean

1. When the conversion result is true

①Any non-0 numeric value (including infinity)

2. When the conversion result is false

①0

②NaN

3.

Object class

type is converted to Boolean1. The conversion result is true Situation

①Any object (including empty objects)

②Array object (including empty arrays)

③

Regular expression

2. When the conversion result is false

①Empty object

PS: This should be distinguished from the previous empty object {}. An empty object means that the object has been created, but there is nothing in it, while an empty object means that it has not been created, which is a null

4. Convert Undefined type to Boolean

1. Can only return false

I believe I read this article You have mastered the case method. For more exciting information, please pay attention to other related articles on the PHP Chinese website!

Recommended reading:

How to use JavaScript strings

How to implement two-way data binding in WeChat applet

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