c++ - Why in Malloc() function it allocated more byte than actual specified? -

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• what purpose of allocating specific amount of memory arrays in c++? 5 answers

i allocates memory using malloc(1) i.e allocated 1 byte accept number more of 1 byte. here in code accept 1000 number , not possible store number in 1 byte. code:

#include <stdio.h> #include <stdlib.h> #include<iostream> using namespace std; int main() {     int *a;      a=(int *)malloc(1);     for(int i=0;i<1000;i++)     {         a[i]=i;     }     for(int i=0;i<1000;i++)     {         cout<<""<<a[i];     } } 

why happen?

it's undefined behavior because c , c++ doesn't boundary checking regards arrays.