Final Variables - Java Tutorial 5.0 英文版

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Final Variables

You can declare a variable in any scope to be final. The value of a final variable cannot change after it has been initialized. Such variables are similar to constants in other programming languages.

To declare a final variable, use the final keyword in the variable declaration before the type.

final int aFinalVar = 0;

The previous statement declares a final variable and initializes it all at once. Subsequent attempts to assign a value to aFinalVar result in a compiler error. You may, if necessary, defer initialization of a final local variable. Simply declare the local variable and initialize it later, as follows.

final int blankfinal;
. . .
blankfinal = 0;

A final local variable that has been declared but not yet initialized is called a blank final. Again, once a final local variable has been initialized, it cannot be set, and any later attempts to assign a value to blankfinal result in a compile-time error.

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