freeCodeCamp/guide/chinese/csharp/for-loop/index.md

title	localeTitle
For Loop	对于循环

对于循环

for循环重复执行代码块，直到指定的条件表达式求值为false。

for循环剖析：

for (initialization; condition; iterator) 
 { 
    body 
 } 

• 初始化 - 初始化语句设置初始条件，并在进入循环体之前仅运行一次。
• condition - 布尔表达式，用于确定循环体是应该再次执行还是循环应该退出。
• iterator - 在循环体的每次迭代后执行。

例1

for (int i = 0; i < 5; i++) 
 { 
    Console.WriteLine("Number " + i); 
 } 

输出：

> Number 0 
 > Number 1 
 > Number 2 
 > Number 3 
 > Number 4 

例2

int j = 0; 
 for (int i = 0; j < 5; i++) 
 { 
    Console.WriteLine("Numbers {0} {1}", i, j); 
    j++; 
 } 

输出：

> Numbers 0 0 
 > Numbers 1 1 
 > Numbers 2 2 
 > Numbers 3 3 
 > Numbers 4 4 

实施例3-实施例2的简化

for (int i = 0, j = 0; i < 5 && j < 5; i++, j++) 
 { 
    Console.WriteLine("Numbers {0} {1}", i, j); 
 } 

输出：

> Numbers 0 0 
 > Numbers 1 1 
 > Numbers 2 2 
 > Numbers 3 3 
 > Numbers 4 4 

例4

for (int i = 5; i > 0; i--) 
 { 
    Console.WriteLine("Number " + i); 
 } 

输出：

> Number 5 
 > Number 4 
 > Number 3 
 > Number 2 
 > Number 1 

例5

// Infinite loop - The loop body is executed infinitely 
 for (; ;) 
 { 
    Console.WriteLine("The universe is infinite"); 
 } 
 
 // Anything after infinite loop is reported as "Unreachable code detected" in Visual Studio 
 Console.WriteLine("Never considered for execution"); 

输出：

> The universe is infinite 
 > The universe is infinite 
 > The universe is infinite 
 > .... 
 > .... 

例6

int i = 0; 
 for (; i < 5;) 
 { 
    Console.WriteLine("Number " + i); 
    i++; 
 } 

输出：

> Number 0 
 > Number 1 
 > Number 2 
 > Number 3 
 > Number 4 

其他资源

• Microsoft文档

结束