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);
50abc20
50abc1010@H_403_5@
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.@H_403_5@
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：@H_403_5@
- 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
