Interview question: when a variable is modified using the final keyword, can the reference not be changed, or can the referenced object not be changed ?, Final keywords

Interview question: when a variable is modified using the final keyword, can the reference not be changed, or can the referenced object not be changed ?, Final keywords

/** Question: when you use the final keyword to modify a variable, whether the reference cannot be changed or the referenced object cannot be changed * answer: * when you use the final keyword to modify a variable, the guiding variables cannot be changed. The content in the object to which the referenced variables point can still be changed. */Public class Test10 {// final modifies the variable public static final char CHAR = '中' of the basic type '; // final modifier public static final StringBuffer a = new StringBuffer ("StringBuffer"); public static void main (String [] args) {// compilation error, reference cannot be changed // a = new StringBuffer ("hehe"); // the content of the object to which the referenced variable points can still be changed.. append ("xxx");} public static int method1 (final int I) {// I = I + 1; // compilation error, because final modifies the return I;} variable of the basic type. // when someone defines a method parameter (reference a variable, you may want to use the following method to prevent internal modification of the passed parameter object. // In fact, this cannot be done, in this method, you can add the following code to modify the parameter object public static void method2 (final StringBuffer buffer) {buffer. append ("buffer"); // compiled because final modifies the variable of the reference type }}