"*" Sign in front of the role of the pointer variable p?
How to understand where the "*" sign it? For example: the door when you get home, you want to come in first thing is to come up with a key to unlock, imagine the security door lock cylinder is not like this "*" sign? You have to use a key to the house, imagine the security door lock cylinder is not like this "*" sign? You have to use a key to enter, then you read / write block of memory is not have a key to it? The "*" symbol is not is the key to our best? When using pointers, without it, you are impossible to read / write a block of memory.
Pointer variable read / write a block of memory, in need thereof by adding "*."
*p = 10；
a = *p；