我对String连接感到困惑.
String s1 = 20 + 30 + "abc" + (10 + 10); String s2 = 20 + 30 + "abc" + 10 + 10; System.out.println(s1); System.out.println(s2);
输出是：
50abc20
50abc1010
我想知道为什么在这两种情况下都会将20 30加在一起,但10 10需要括号才能被添加(s1)而不是连接到字符串(s2).请解释String运算符如何在这里工作.
解决方法
加法是左联的.采取第一种情况
20+30+"abc"+(10+10)
----- -------
50 +"abc"+ 20 <--- here both operands are integers with the + operator,which is addition
---------
"50abc" + 20 <--- + operator on integer and string results in concatenation
------------
"50abc20" <--- + operator on integer and string results in concatenation
在第二种情况：
20+30+"abc"+10+10
-----
50 +"abc"+10+10 <--- here both operands are integers with the + operator,which is addition
---------
"50abc" +10+10 <--- + operator on integer and string results in concatenation
----------
"50abc10" +10 <--- + operator on integer and string results in concatenation
------------
"50abc1010" <--- + operator on integer and string results in concatenation
