Objective-C对象的本质

Objective-C对象的本质是指向某块堆(heap)内存中数据的指针, 因为是指针, 顾在声明时, 通常会带有*:

// 变量pointerVariable"指向"(point to)SQIObject类型的实例
SQIObject *pointerVariable = [SQIObject new];

所有Objective-C对象都是如此, 若想直接把对象所需的内存分配在栈(stack)上, 编译器会直接报错:

// error: interface type cannot be statically allocated
SQIObject stackVariable = [SQIObject new];