java - 在java错误中创建新对象

Question

我主要写了这段代码:

if (startAmount>0) //create new cashier object with or without a start amount
    Cashier newCashier = new Cashier(startAmount);
else Cashier newCashier = new Cashier();

第二行和第三行出现编译错误:

Multiple markers at this line
    - Cashier cannot be resolved to a variable
    - Syntax error on token "newCashier", delete

和:

Multiple markers at this line
    - Cashier cannot be resolved to a variable
    - Syntax error, insert "AssignmentOperator Expression" to complete 
     Assignment
    - Syntax error, insert ";" to complete Statement

但是当我用括号写这样的代码时:

if (startAmount>0)//create new cashier object with or without a start amount
{
    Cashier newCashier = new Cashier(startAmount);
}
else{ Cashier newCashier = new Cashier();}

好像没问题，没有编译错误。谁能帮我理解为什么？

Answer 1

为什么要为 newCachier 引用创建影子变量，你宁愿这样做

Cashier newCashier = null;
if (startAmount>0) //create new cashier object with or without a start amount
    newCashier = new Cashier(startAmount);
else 
     newCashier = new Cashier();