IL代码，

.assembly extern mscorlib {}.assembly Test{.ver 1:0:1:0}.module test.exe.method static void main() cil managed{.maxstack 8.entrypoint.locals init (int32, int32)ldc.i4 4stloc.0        //Upper    limit of the Loop, total 5 ldc.i4 0 stloc.1        //Initialize the Starting of loop Start:     //Check if the Counter exceedsldloc.1 ldloc.0 bgt Exit //If Second variable exceeds the first variable, then exitldloc.1call void [mscorlib]System.Console::WriteLine(int32)//Increase the Counterldc.i4 1ldloc.1addstloc.1br Start
Exit:    ret
}

构建运行如下；

 我还不是太理解，循环的开始和结束值是不是装入栈；循环变量加1也是在栈上操作；循环中啥也没干，只是输出了循环变量值；bgt、br是跳转语句；有时间继续；