Ternary Operators in Solidity

A ternary operator or conditional operator in solidity is an operator that takes three operands. Ternary operators come in handy if the programmer wants to write a simple if-else statement in a single line.

Syntax 1: Ternary Operator

condition  ? statement 1 : statement 2;

If the condition is true then execute statement 1, else execute statement 2. 

Syntax 2: Ternary Operator Chaining

(condition 1)  ? statement 1 : (  (condition 2) ? statement 2 : statement 3) ;

Using Ternary Operator in Solidity

Below is the Solidity program to implement the ternary operator:

Solidity

// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.8.6 <0.9.0;
/// @title A contract for demonstrate the Solidity Operator
/// @notice For now, this contract just show how to implement Ternary Operator
contract SolidityTest {
    constructor() {}

    function getResult() public pure returns (string memory) {

        // This code returns a string
        // if a > b we return "a is bigger"
        // else we return "b is bigger"
        uint256 a = 100;
        uint256 b = 200;
        return (a > b ? "a is bigger" : "b is bigger");
    }
}

Explanation: In the above code, we find the bigger of the two numbers a and b. If a > b we return a string “a is bigger” else we return the string “b is bigger” Here the condition of the ternary operator is a>b, statement 1 is “a is bigger” and statement 2 is “b is bigger”.

Output:

“b is bigger”

Chaining Ternary Operator in Solidity

The ternary operator can also be chained to check if a and b are equal this time. Below is the Solidity program to implement the above approach:

Solidity

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.8.6 <0.9.0;

// @title A contract for demonstrate the Solidity Operator
// @notice For now, this contract just show how to
// implement Ternary Operator chaining
contract SolidityTest {
    constructor() {}

    function getResult() public pure returns (string memory) {

        // This code returns a string
        // if a > b we return "a is bigger"
        // else if a == b we return "a and b are equal"
        // else b > a we return "b is bigger"
        uint256 a = 100;
        uint256 b = 100;

        return (a > b ? "a is bigger" : ( (a==b) ?
                "a and b are equal" : "b is bigger" ) );
    }
}

Explanation: 

• condition 1 is a>b and condition 2 is a==b
• statement 1 is “a is bigger”, statement 2 is “a and b are equal” and statement 3 is “b is bigger”

Output: 

“a and b are equal”