c++ - What is the significance of comma in array and structure initialization? -

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• int a[] = {1,2,}; weird comma allowed. particular reason? 17 answers

while browsing through codes, came across method of initialization:

#include<stdio.h>  struct trial{     int x, y; };  int main(){     int a[10] = {0,1, };//comma here     struct trial z = {1, };//comma here     return 0; } 

what significance of comma operator? not find difference in method of initialization if comma operator removed.

it makes sense if generate such code scripts. keeps script simple. no edge-cases. in particular, don't bother whether need add , first, before writing 1 more item; write 1 item followed comma , you're done!

you don't care first item or last item. items same if there trailing comma.

think code-generation point of view. start making sense.

see python script generates such code:

print ("int a[] = {") item in items:     print (item + ",") print ("};") 

it simple. try writing code without trailing comma. wouldn't that simple.

the standard allows trailing-comma in enum definition:

enum {     x,     y,     z, //last item : comman okay }; 

hope helps.