If you don't know the number of elements in the array, it is usually an int array or a char array. See the following code implementation requirements:

# include & ltstdio.h & gt

Invalid? Master ()

{

int？ num[]={ 1，2，3 }；

Charles? str[]={'4 '，' 5 '，' 6 ' }；

for(int？ I = 0； I< sizeof (num)/sizeof (int); I++)//sizeof(num)/sizeof(int) calculation length

{

printf("%d？" ，num[I])；

}

puts(" ")；

for(I = 0； I< sizeof (str)/sizeof (char); i++)

{

printf("%c？ ，str[I])；

}

puts(" ")；

} If it is a string array, you can use str[i]! =0 to determine whether it reaches the tail, so there is no such thing as the number of elements.