Solidity - View Functions

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View functions ensure that they will not modify the state. A function can be declared as view. The following statements if present in the function are considered modifying the state and compiler will throw warning in such cases.

  • Modifying state variables.

  • Emitting events.

  • Creating other contracts.

  • Using selfdestruct.

  • Sending Ether via calls.

  • Calling any function which is not marked view or pure.

  • Using low-level calls.

  • Using inline assembly containing certain opcodes.

Getter method are by default view functions.

See the example below using a view function.

Example

pragma solidity ^0.5.0;

contract Test {
   function getResult() public view returns(uint product, uint sum){
      uint a = 1; // local variable
      uint b = 2;
      product = a * b;
      sum = a + b; 
   }
}

Run the above program using steps provided in Solidity First Application chapter.

Output

0: uint256: product 2
1: uint256: sum 3
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