cadence

		
			// Contract file: Counter.cdc
// Deployed to 0x01
pub contract Counter {
   pub var count: Int

   pub fun increment() {
      self.count = self.count + 1
   }

   pub fun decrement() {
      self.count = self.count - 1
   }

   pub fun get(): Int {
      return self.count
   }
}

cadence

		
			// Transaction file: increment.cdc
import Counter from 0x01

transaction() {

   let SignerAddress: Address

   prepare(signer: AuthAccount) {
      self.SignerAddress = signer.address
   }

   execute {
      Counter.increment()
      log(self.SignerAddress) // prints the signer's address
   }
}

Transactions

In order to change data in a contract, you need to send a transaction.

In Cadence, transactions (and scripts) are separate from the contract layer, and are written in different files.

Transactions have 2 main stages:

prepare - to access data/information inside the signer’s account (allowed by the AuthAccount type)
execute - to execute actions