考察下面的代码，下面的代码将会输出不同的值。[code]public class JavaLangIntegerType {
void test_decode() {
int val = 0;
val = Integer.decode(“1”); System.out.println("val = " + val); //返回1
val = Integer.decode(“2”); System.out.println("val = " + val); //返回2
val = Integer.decode(“0xa”); System.out.println(“val = " + val); //返回10
val = Integer.decode(“0xb”); System.out.println(“val = " + val); //返回11
val = Integer.decode(”-1”); System.out.println("val = " + val); //返回-1
//val = Integer.decode(“a”); System.out.println("val = " + val); //抛出 NumberFormatException
}
void test_parseInt() {
Integer val = null;
val = Integer.parseInt(“0”, 10); System.out.println(“val = " + val); //返回 0
val = Integer.parseInt(“473”, 10); System.out.println(“val = " + val); //返回 473
val = Integer.parseInt(”-0”, 10); System.out.println(“val = " + val); //返回 0
val = Integer.parseInt(“FC”, 16); System.out.println(“val = " + val); //返回252
val = Integer.parseInt(”-FF”, 16); System.out.println("val = " + val); //返回 -255
val = Integer.parseInt(“1100110”, 2); System.out.println(“val = " + val); //返回 102
val = Integer.parseInt(“2147483647”, 10); System.out.println(“val = " + val); //返回 2147483647
val = Integer.parseInt(”-2147483648”, 10); System.out.println("val = " + val); //返回 -2147483648
val = Integer.parseInt(“Kona”, 27); System.out.println("val = " + val); //返回 411787
//Integer.parseInt(“2147483648”, 10); //抛出 NumberFormatException
//Integer.parseInt(“99”, 8); //抛出 NumberFormatException
//Integer.parseInt(“Kona”, 10); //抛出 NumberFormatException
}
void test_toHexString() {
String str = null;
str = Integer.toHexString(0); System.out.println("str = " + str); //返回0
str = Integer.toHexString(10); System.out.println("str = " + str); //返回a
str = Integer.toHexString(20); System.out.println("str = " + str); //返回14
str = Integer.toHexString(30); System.out.println("str = " + str); //返回1e
str = Integer.toHexString(-1); System.out.println("str = " + str); //返回ffffffff
str = Integer.toHexString(-2); System.out.println("str = " + str); //返回fffffffe
}
void test_toString() {
String str = null;
str = Integer.toString(1, 10); System.out.println("str = " + str); //返回1
str = Integer.toString(10, 10); System.out.println("str = " + str); //返回10
str = Integer.toString(10, 16); System.out.println("str = " + str); //返回a
str = Integer.toString(20, 10); System.out.println("str = " + str); //返回20
str = Integer.toString(20, 16); System.out.println("str = " + str); //返回14
str = Integer.toString(30, 10); System.out.println("str = " + str); //返回30
str = Integer.toString(30, 16); System.out.println("str = " + str); //返回1e
str = Integer.toString(-1, 10); System.out.println("str = " + str); //返回-1
str = Integer.toString(-2, 16); System.out.println("str = " + str); //返回-2
}
void test_valueOf() {
Integer val = null;
val = Integer.valueOf(0); System.out.println("val = " + val); //返回0
val = Integer.valueOf(1); System.out.println("val = " + val); //返回 1
val = Integer.valueOf(10); System.out.println("val = " + val); //返回 10
val = Integer.valueOf(20); System.out.println("val = " + val); //返回 20
val = Integer.valueOf(30); System.out.println("val = " + val); //返回 30
val = Integer.valueOf(-1); System.out.println("val = " + val); //返回 -1
val = Integer.valueOf(“0”); System.out.println("val = " + val); //返回 0
val = Integer.valueOf(“1”); System.out.println("val = " + val); //返回1
val = Integer.valueOf(“10”); System.out.println("val = " + val); //返回10
val = Integer.valueOf(“20”); System.out.println(“val = " + val); //返回20
val = Integer.valueOf(“30”); System.out.println(“val = " + val); //返回30
val = Integer.valueOf(”-1”); System.out.println("val = " + val); //返回-1
val = Integer.valueOf(“0”, 16); System.out.println("val = " + val); //返回0
val = Integer.valueOf(“1”, 16); System.out.println("val = " + val); //返回1
val = Integer.valueOf(“10”, 16); System.out.println("val = " + val); //返回10
val = Integer.valueOf(“20”, 16); System.out.println(“val = " + val); //返回20
val = Integer.valueOf(“30”, 16); System.out.println(“val = " + val); //返回30
val = Integer.valueOf(”-1”, 16); System.out.println("val = " + val); //返回-1
}
}[/code]