String 的理解

* b无法被编译器优化，只有在程序运行期来动态分配并将连接后的新地址赋给b。所以上面程序的结果也就为false。

*/

String A = "ab";

String B = "b";

String C = "a" + B;

System.out.println(A + "\t" + C + "\t" + (A == C));// false

System.out.println(A + "\t" + C + "\t" + (A.equals(C)));// true

?

/*************************************************************/

?

String AA = "ab";

final String BB = "b";

String CC = "a" + BB;

System.out.println(AA + "\t" + CC + "\t" + (AA == CC));// true

?

String AAA = "ab";

String CCC = "a" + "b";

System.out.println(AAA + "\t" + CCC + "\t" + (AAA == CCC));// true

?

String AAAA = "ab";

final String BBBB = getBBBB();

String CCCC = "a" + BBBB;

System.out.println((AAAA == CCCC)); // false

?

int a1 = 3;

int b1 = 2;

int c1 = 1 + b1;

System.out.println(a1 + "\t" + b1 + "\t" + c1 + "\t" + (a1 == c1));// true

}

?

private static String getBBBB() {

return "b";

}