How do you refer to a contract own address inside it?

Question

I am attempting to use 2 contracts together, and I need my 2nd contract to pass his own address to the first contract.

Is there an easy way to do this? Like this.address?

Or should I update my contract own address into a variable?

Answer 1

Solidity v5 Update

As of Solidity v5, this become deprecated. You now have to use address(this).

Solidity v4 and older

Get contract address in Solidity

Short answer: The global variable this is the contract address.

Long answer: this is a variable representing the current contract. Its type is the type of the contract. Since any contract type basically inherits from the address type, this is always convertible to address and in this case contains its own address.

Answer 2

I tried this and this.address but found the following works:

function transferTo(address receiver, uint amount) {
    if (   amount == 0
        || receiver == address(this) )
        return;

Answer 3

If you're looking for an assembly (yul) answer:

contract ContractAddress {

    address public disAddress;

    constructor() public {
        assembly {
            sstore(disAddress_slot, address)
        }
    }
}

Notice the address on the 7th line? That refers to the contract's own address. Test it yourself in Remix.