• store data within contracts
• hold multiple type of values
• e.g , in decentralised uber (on eth blockchain), you will store rides, uses, locations, etc of user on the smart contract.

Types of Variables

1. Unsigned Number:

• are the positive number, which can be store in a variable.

• it can never be a negative variable

  • uint8: 8 bit numbers
  • uint16: 16 bit numbers
  • uint256/uint: 256 bit numbers

• e.g

contract Sum {
	uint8 gender;
	uint16 calls;
	uint number = 12345678;
}

2. Signed Numbers:

• are all the number whether it is +ve or -ve
  • int32: 32 bit number
  • int256/ int: 256 bit number
• e.g

contract Sum {
	int32 = 784  ;
	int number = -12345678;
}

3. Booleans:

• true or fasle
• e.g