C++ Array Size
Get the Size of an Array
To get the size of an array, you can use the sizeof()
operator:
Example
int myNumbers[5] = {10, 20, 30, 40, 50};
cout << sizeof(myNumbers);
Result:
20
Why did the result show 20 instead of
5, when the array contains 5 elements?
It is because the sizeof() operator returns the size of a type in
bytes.
You learned from the Data Types chapter that an int
type is usually 4 bytes, so from the example above, 4 x 5 (4 bytes x 5 elements) = 20 bytes.
To find out how many elements an array has, you have to divide the size of the array by the size of the data type it contains:
Example
int myNumbers[5] = {10, 20, 30, 40, 50};
int getArrayLength =
sizeof(myNumbers) / sizeof(int);
cout << getArrayLength;
Result:
5
