"Java" basic data types and encapsulation classes, string conversions __java basic data types and their encapsulation class strings

one, the conversion between the basic data type and its corresponding encapsulation class basic data types are converted to encapsulated classes

1 • Direct Assignment (automatic packaging)

Integer i=3;

2 • Using the enclosing parameter constructor of the encapsulated class (instantiated)

Integer i=new integer (3);

3 • Use the valueof () method provided by the encapsulation class (static method)

Integer i=integer.valueof (3);

encapsulate class to basic data type

1. Direct assignment (Automatic unpack)

Integer i=new integer (2);

int j=i;

2 • Use the value () method provided by the encapsulation class

Integer i=new integer (3);

int J=i.intvalue ();

float F=i.floatvalue ();

ii. conversion between basic data types and strings Convert base data type to String

1 • Using the valueof () method of the String class (static method)

String s=string.valueof (123);

2 • Use the ToString () method of the encapsulated class (static method)

String s=integer.tostring (3);

3 • Use string connector "+"

String s= "" +123;

string conversion to basic data type

1. Use the static method of the encapsulation class

int I=integer.parseint ("12");

third, the encapsulation class and the string between the conversion string conversion to encapsulated class

1 • Using the enclosing parameter constructor of the encapsulated class (instantiated)

Integer i=new integer ("123");

2 • Using the valueof () method of the Encapsulation class

Integer i=integer.valueof ("123");

encapsulate class to String

1 • Use string connector "+"

Integer i=new integer (123);

String s= "" +i;

2 • Using the ToString () method of the encapsulated class

Integer i=new integer (123);

String s=i.tostring ();