55 lines
1.1 KiB
Markdown
55 lines
1.1 KiB
Markdown
|
---
|
||
|
|
title: Do...While Loop
|
||
|
|
localeTitle: 做......循环
|
||
|
|
---
|
||
|
|
# 做......循环
|
||
|
|
|
||
|
|
`do while`类似于`while`循环，但是在检查给定条件之前，保证语句组至少运行一次。 需要注意的一点是'while'循环是一个退出控制循环。虽然（它不一定会执行），'do while'是一个入口控制循环（它将至少执行一次，即使条件不是真的）。
|
||
|
|
|
||
|
|
```java
|
||
|
|
do
|
||
|
|
{
|
||
|
|
// Statements
|
||
|
|
}
|
||
|
|
while (condition);
|
||
|
|
```
|
||
|
|
|
||
|
|
## 例
|
||
|
|
|
||
|
|
```java
|
||
|
|
int iter_DoWhile = 20;
|
||
|
|
do
|
||
|
|
{
|
||
|
|
System.out.print (iter_DoWhile + " ");
|
||
|
|
|
||
|
|
// Increment the counter
|
||
|
|
iter_DoWhile++;
|
||
|
|
}
|
||
|
|
while (iter_DoWhile < 10);
|
||
|
|
System.out.println("iter_DoWhile Value: " + iter_DoWhile);
|
||
|
|
```
|
||
|
|
|
||
|
|
输出：
|
||
|
|
```
|
||
|
|
20
|
||
|
|
iter_DoWhile Value: 21
|
||
|
|
```
|
||
|
|
|
||
|
|
**记住** ：执行一次代码体之后检查`do-while`循环的条件。
|
||
|
|
|
||
|
|
 [运行代码](https://repl.it/CJYl/0)
|
||
|
|
|
||
|
|
## 行使
|
||
|
|
|
||
|
|
你能猜出以下代码片段的输出吗？
|
||
|
|
|
||
|
|
```java
|
||
|
|
int i = 10;
|
||
|
|
do
|
||
|
|
{
|
||
|
|
System.out.println("The value of i is " + i);
|
||
|
|
i--;
|
||
|
|
}
|
||
|
|
while (i >= 10);
|
||
|
|
|
||
|
|
```
|