const的应用

const的应用

例如：

void main()
{
	int a = 10, b = 20;
	int *p1 = &a;
	*p1 = 100;
	p1 = &b;
	const int *p2 = &a;//*p不可改变,p可以改变
	int const *p3 = &a; //*p不可改变, p可以改变
	int * const p4 = &a;//*p可改变,p不可以改变
	const int * const p5 = &a;//*p不可改变,p不可以改变
	*p2 = 200;
	p2 = &b;
	*p3 = 200;
	p3 = &b;
	*p4 = 200;
	p4 = &b;
	p5 = &b;
	*p5 = 200;
}*/