如何将字符串转换为存储在整数数组中？

Question

如何将诸如gcardNum之类的字符串转换为存储在整数数组中？

char gcardNum[17] = ""; //16 digit gift card number
printf("What is your 16 digit gift card number?\n"); 
scanf("%s", gcardNum); // asks the user for their 16 digit gc number