Function: transferFrom(address _from, address _to, uint256 _value)

Transfer a specified amount of tokens from one address to another.

Inputs

• _from

  • Control: Controlled by the user.

  • Constraints: Cannot be the zero address, and the _from address must have approved the caller to spend at least _value amount of tokens.

  • Impact: The address will cost the specified _value of tokens.

• _to

  • Control: Controlled by the user.

  • Constraints: Cannot be the zero address.

  • Impact: The address will receive the specified _value of tokens.

• _value

  • Control: Controlled by the user.

  • Constraints: Must be a nonnegative integer and less than or equal to the _from address's balance and the allowed amount.

  • Impact: The number of tokens to transfer from the _from address to the _to address.

Branches and code coverage (including function calls)

Intended branches

• Successful transfer.

  Test coverage

Negative behavior

• Insufficient allowance.

  Negative test

• Insufficient balance.

  Negative test

• Transfer from/to zero address.

  Negative test