函数指针作为qsort函数的参数
[英]Function pointer as parameter of qsort function
at the qsort function in c there is a functin pointer to the compare function, which actually sorts the data of the array given.
在c中的qsort函数中有一个指向compare函数的functin指针，它实际上对给定数组的数据进行排序。
so inside that function i see:
所以在这个功能里面我看到：
if ( *(MyType*)a < *(MyType*)b ) return -1;
Well i understand a will casted to MyType* but what about the star after that on the very left? what is it doing?
好吧，我明白了一个将会转移到MyType *但是在那之后左边的那个明星怎么样？它在做什么？
Well, i guess this just dereference the pointer a?
好吧，我想这只是取消引用指针a？
thx.
谢谢。
/me
/我
1 个解决方案
#1
2
Well i understand a will casted to MyType* but what about the star after that on the very left? what is it doing?
好吧，我明白了一个将会转移到MyType *但是在那之后左边的那个明星怎么样？它在做什么？
So you know a is a pointer and pointer holds some valid memory location the value stored in that memory location is fetched by using the * operator which is called Dereferencing a pointer
所以你知道a是一个指针和指针保存一些有效的内存位置，通过使用*运算符获取存储在该内存位置的值，该运算符称为解引用指针
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