[英]How to delete in char pointer array in C
I want to delete the cell which has "sth" in: 我想删除“sth”中的单元格:
char* a[200];
how should I do it? 我该怎么办? I tried this but it does not work!
我试过这个,但它不起作用!
for(i=0;i<100;ti++)
{
if(strcmp(a[i],"sth")!=0)
temp[i]=a[i];
}
a=temp //not sure here
You cannot delete a cell from an array like this. 您不能从这样的数组中删除单元格。 You can set it instead to something arbitrary, like an empty string.
您可以将其设置为任意值,例如空字符串。
The harder way is: 更难的方法是:
You may wonder why is a simple thing like this is so complicated. 你可能想知道为什么像这样的简单事情是如此复杂。 The reason is that the array is a sequence of data in the memory.
原因是数组是存储器中的数据序列。 It works something like a bureau with a lot of drawers.
它的工作方式就像一个有很多抽屉的局。 You can tell the program what to put in the drawers, but you can't really get rid only a part of it without destroying the whole bureau.
你可以告诉程序什么放在抽屉里,但你不能真正摆脱它的一部分而不破坏整个局。 So you have to make a new one.
所以你必须做一个新的。
something like 就像是
j=0;
for(i=0;i<100;i++)
{
a[j]=a[i];
if(strcmp(a[i],"sth")) {
j++;
}else{
a[j]=0;
}
}
i didnt free the memory here, since i dont know where the strings came from. 我没有释放内存,因为我不知道字符串来自哪里。 If the strings were allocated with malloc they should be freed (if not used elsewhere)
如果字符串是用malloc分配的,那么它们应该被释放(如果没有在其他地方使用)
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