A brief discussion on C + + array passing methods cannot be computed to the correct array size with sizeof

In C + + we often use sizeof () to calculate the size of an array

For example:

1#include <iostream>2 using namespacestd;3 4 voidLength (int*p)5 {6cout<<sizeof(p) <<"  "<<sizeof(int) <<Endl;7 }8 9 intMain ()Ten { One     intN; A     intPirce[] = {0,1,5,8,9,Ten, -, -, -, -, -}; -  -      for(intI=0; i<sizeof(Pirce)/sizeof(int); i++) the     { -cout<<pirce[i]<<" "; -     } -cout<<Endl; +  - Length (pirce); +  A     return 0; at}

The result of running this code is as follows:

0 1 5 8 9 10 17 17 20 24 30

8 4

It can be seen in the main method that sizeof (Pirce)/sizeof (int) is correct and it prints out the elements in the array so

Passing an array in the length () method finds the result of sizeof (p)/sizeof (int) to be 2

Why???

This is because the array is passed into the method with the first address of the array, so it becomes a pointer, so it is not possible to use sizeof to calculate the size of the group.

Ps: The array here is a static array, not a new array;

A brief discussion on C + + array passing methods cannot be computed to the correct array size with sizeof