array syntax in c++

int foo [] = { 16, 2, 77, 40, 12071 };

// Array declaration by specifying size and initializing 
// elements 
int arr[6] = { 10, 20, 30, 40 } 
  
// Compiler creates an array of size 6, initializes first 
// 4 elements as specified by user and rest two elements as 0. 
// above is same as  "int arr[] = {10, 20, 30, 40, 0, 0}" 

// Array declaration by initializing elements 
int arr[] = { 10, 20, 30, 40 } 
  
// Compiler creates an array of size 4. 
// above is same as  "int arr[4] = {10, 20, 30, 40}" 

int foo[] = { 10, 20, 30 };
int foo[] { 10, 20, 30 }; 

int bar [5] = { 10, 20, 30 };