【性能优化】遍历数组：用pointer指针遍历 代替 index下标遍历

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1. 下标方式遍历数组：

void index_visit_array()
{
	typedef struct tagNodeST
	{
		unsigned int uix;
		float fy;
		char cz;
		int magic[4];
	}NODE_ST;

	NODE_ST astNodes[10];
	int len = sizeof(astNodes) / sizeof(astNodes[0]);

	//index way visit node element in array
	for(int i = len; i--;)
	{
		astNodes[i].uix = 0;
		astNodes[i].fy = 0.f;
		astNodes[i].cz = 0;
	}

	return;
}

2.指针方式遍历数组

void pointer_visit_array()
{
	typedef struct tagNodeST
	{
		unsigned int uix;
		float fy;
		char cz;
		int magic[4];
	}NODE_ST;

	NODE_ST astNodes[10];
	int len = sizeof(astNodes) / sizeof(astNodes[0]);

	//pointer way visit node element in array
	NODE_ST* start = astNodes;
	const NODE_ST* const max = astNodes + len - 1;
	while (start <= max)
	{
		start->uix = 0;//*(unsigned int*)start = 0;
		start->fy = 0.f;
		start->cz = 0;

		++start;
	}


	return;
}

一般情况下可以使用指针遍历数组来代替下标遍历数组，提高性能。

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