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This article shares with you the content of a sample analysis of JSP data types and conversion rules. The editor thinks it is very practical, so share it with you as a reference and follow the editor to have a look.

JSP data type

There are four basic types:

Int length data types are: byte (8bits), short (16bits), int (32bits), long (64bits),

Float length data types are: single precision (32bits float), double precision (64bits double)

The values of boolean type variables are: ture, false

Char data types are: unicode characters, 16 bits

Corresponding class types: Integer, Float, Boolean, Character, Double, Short, Byte, Long

Principles of JSP data type conversion

Conversion from low precision to high precision

Byte, short, int, long, float, double, char Note: when two chars operate, they are automatically converted to int; when char operates with other types, they are automatically converted to int, and then other types are automatically converted.

Conversion from basic type to class type

Forward conversion: new a variable of a new class type through a class wrapper

Integer a = new Integer (2)

Reverse conversion: converting through a class wrapper

Int b=a.intValue ()

Conversion of class types to strings

Forward conversion: because each class is a subclass of the object class, and all object classes have a toString () function, you can convert it through the toString () function.

Reverse conversion: a variable of a new class type is generated through the class wrapper new

Eg1: int i=Integer.valueOf ("123"). IntValue ()

JSP data type description: the above example converts a string into an Integer object, and then calls the object's intValue () method to return its corresponding int value.

Eg2: float f=Float.valueOf ("123"). FloatValue ()

JSP data type description: the above example converts a string into a Float object, and then calls the object's floatValue () method to return its corresponding float value.

Eg3: boolean b=Boolean.valueOf ("123"). BooleanValue ()

JSP data type description: the above example converts a string into a Boolean object, and then calls the object's booleanValue () method to return its corresponding boolean value.

Eg4:double d=Double.valueOf ("123"). DoubleValue ()

JSP data type description: the above example converts a string into a Double object, and then calls the object's doubleValue () method to return its corresponding double value.

Eg5: long l=Long.valueOf ("123"). LongValue ()

JSP data type description: the above example converts a string into a Long object, and then calls the object's longValue () method to return its corresponding long value.

Eg6: char=Character.valueOf ("123"). CharValue ()

JSP data type description: the above example converts a string into a Character object, and then calls the object's charValue () method to return its corresponding char value.

Conversion from basic type to string

Forward conversion of JSP data type:

Such as:

Int axiom 12; String baking bacca + ""

Reverse conversion of JSP data types:

Through the class wrapper

Eg1:int i=Integer.parseInt ("123")

JSP data type description: this method can only be used to convert strings to integer variables

Eg2: float f=Float.valueOf ("123"). FloatValue ()

JSP data type description: the above example converts a string into a Float object, and then calls the object's floatValue () method to return its corresponding float value.

Eg3: boolean b=Boolean.valueOf ("123"). BooleanValue ()

JSP data type description: the above example converts a string into a Boolean object, and then calls the object's booleanValue () method to return its corresponding boolean value.

Eg4:double d=Double.valueOf ("123"). DoubleValue ()

JSP data type description: the above example converts a string into a Double object, and then calls the object's doubleValue () method to return its corresponding double value.

Eg5: long l=Long.valueOf ("123"). LongValue ()

JSP data type description: the above example converts a string into a Long object, and then calls the object's longValue () method to return its corresponding long value.

Eg6: char=Character.valueOf ("123"). CharValue ()

JSP data type description: the above example converts a string into a Character object, and then calls the object's charValue () method to return its corresponding char value.

Thank you for reading! This is the end of this article on "sample analysis of JSP data types and conversion rules". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, you can share it out for more people to see!

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