循环体中申明变量

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今天在看java代码时发现一句

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while()
{
	final A a=other.getA();
}

疑惑之处：final为不可更改，那么循环体循环回来时是更改还是新建呢？

C语言代码中：

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int main(void)
{	
	int i;
	for(i=0;i<10;i++)
	{
		int k;
		printf("%d ",k);
		k++;
	}
 } 
 
int main(void)
{
	int i;
	for(i=0;i<10;i++)
	{
		int k;
		printf("%d ",&k);
		k++;
	}
 }

输出为连续的10个数，10个一样的地址
反汇编结果为：

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.text:00401520 _main           proc near               ; CODE XREF: ___tmainCRTStartup+269p
.text:00401520                 push    ebp
.text:00401521                 mov     ebp, esp
.text:00401523                 and     esp, 0FFFFFFF0h
.text:00401526                 sub     esp, 20h
.text:00401529                 call    ___main
.text:0040152E                 mov     dword ptr [esp+1Ch], 0
.text:00401536                 jmp     short loc_401568
.text:00401538 ; ---------------------------------------------------------------------------
.text:00401538
.text:00401538 loc_401538:                             ; CODE XREF: _main+4Dj
.text:00401538                 lea     eax, [esp+18h]
.text:0040153C                 mov     [esp+4], eax
.text:00401540                 mov     dword ptr [esp], offset aD ; "%d "
.text:00401547                 call    _printf
.text:0040154C                 mov     dword ptr [esp], offset a123456 ; "123456"
.text:00401553                 call    _printf
.text:00401558                 mov     eax, [esp+18h]
.text:0040155C                 add     eax, 1
.text:0040155F                 mov     [esp+18h], eax
.text:00401563                 add     dword ptr [esp+1Ch], 1
.text:00401568
.text:00401568 loc_401568:                             ; CODE XREF: _main+16j
.text:00401568                 cmp     dword ptr [esp+1Ch], 9
.text:0040156D                 jle     short loc_401538
.text:0040156F                 leave
.text:00401570                 retn
.text:00401570 _main           endp

变量在循环体外声明时的反编译结果：

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text:00401520 _main           proc near               ; CODE XREF: ___tmainCRTStartup+269p
.text:00401520                 push    ebp
.text:00401521                 mov     ebp, esp
.text:00401523                 and     esp, 0FFFFFFF0h
.text:00401526                 sub     esp, 20h
.text:00401529                 call    ___main
.text:0040152E                 mov     dword ptr [esp+1Ch], 0
.text:00401536                 jmp     short loc_401568
.text:00401538 ; ---------------------------------------------------------------------------
.text:00401538
.text:00401538 loc_401538:                             ; CODE XREF: _main+4Dj
.text:00401538                 lea     eax, [esp+18h]
.text:0040153C                 mov     [esp+4], eax
.text:00401540                 mov     dword ptr [esp], offset aD ; "%d "
.text:00401547                 call    _printf
.text:0040154C                 mov     dword ptr [esp], offset a123456 ; "123456"
.text:00401553                 call    _printf
.text:00401558                 mov     eax, [esp+18h]
.text:0040155C                 add     eax, 1
.text:0040155F                 mov     [esp+18h], eax
.text:00401563                 add     dword ptr [esp+1Ch], 1
.text:00401568
.text:00401568 loc_401568:                             ; CODE XREF: _main+16j
.text:00401568                 cmp     dword ptr [esp+1Ch], 9
.text:0040156D                 jle     short loc_401538
.text:0040156F                 leave
.text:00401570                 retn
.text:00401570 _main           endp

java代码中：

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public class Main{
	public static void main(String[] args)
	{
		int[] l=new int[]{1,2,3,4,5,6,7,8,9,10};
		
		for (int i = 0; i < 10; i++) {
			
			final int a=l[i];
		
			System.out.println(a);
		}		
	}
	
	
}

结果为运行无误1-10

结论

c语言中，在内在外除了初始化次数区别和作用域区别外其他都一样，不是重复声明
java中。。。。仔细想一下应该是不重新分配栈里的…..要不然太浪费栈了，java对栈的保护应该相当严密