<identifier>预期;无法在类中更新/设置值

Question

对于以下代码，我收到错误

  

“预期的标识符”

public class ConstructorChecking{     
    int a = 7;   
    int b=90;   
    String s="no";      
    a=a+1;   // for this line I am getting the error; why can't I update the value of a? 
}

Answer 1

本声明：

a=a+1;

在该范围内无效

在方法或构造函数中移动它......

而不是 a = a + 1; 执行 a ++;

Answer 2

您可以使用init块

 int a = 7;   
    int b=90;   
    String s="no";      
    {
        a=a+1;   // for this line I am getting the error; why can't I update the value of a? 
    }