How to delete in char pointer array in C

Question

I want to delete the cell which has "sth" in:

char* a[200];

how should I do it? I tried this but it does not work!

for(i=0;i<100;ti++)
{

 if(strcmp(a[i],"sth")!=0)
    temp[i]=a[i];
}
a=temp  //not sure here

Answer 1

You cannot delete a cell from an array like this. You can set it instead to something arbitrary, like an empty string.

The harder way is:

• count the items you want to delete
• create a new smaller array
• copy the items you need from the old array to the new one
• delete the old one.

You may wonder why is a simple thing like this is so complicated. The reason is that the array is a sequence of data in the memory. It works something like a bureau with a lot of drawers. 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. So you have to make a new one.

Answer 2

something like

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. If the strings were allocated with malloc they should be freed (if not used elsewhere)