Pointers and const

Rule: ✅ const binds to left side; if none, binds to right.

1) Pointer to const (data const)

int a=10,b=20;
const int *p = &a;

• can change pointer ✅
• cannot change data through p ❌

p = &b;   // ✅
*p = 5;   // ❌

2) Const pointer (pointer const)

int * const p = &a;

• cannot change pointer ❌
• can change data ✅

*p = 5;  // ✅
p = &b;  // ❌

3) Const pointer to const data

const int * const p = &a;

Both cannot change.

Summary table

Reading trick (right to left)

• int * const p → p is const pointer to int
• const int * p → p is pointer to const int