java - 为什么它是连接而不是算术运算？

Question

Scanner sal = new Scanner(System.in);
System.out.print("Enter first_salary: ");
int Salary1 = sal.nextInt();

System.out.print("Enter second_salary : ");
int Salary2 = sal.nextInt();

System.out.print("Combined Salary is " + Salary1 + Salary2);

我试图让用户输入两次，然后打印总和。相反，输出是连接数字而不是实际相加。

Answer 1

因为 + 运算符从左到右关联。你的论点等同于明确的

(("Combined Salary is " + Salary1) + Salary2)

由于 ("Combined Salary is "+ Salary1) 产生一个字符串，您将连接字符串。要进行不同的分组，请使用括号调整运算顺序:

System.out.print("Combined Salary is " + (Salary1 + Salary2));