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Test3.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

contract IfElse {
    function foo(uint x) public pure returns (uint) {
        if (x < 10) {
            return 0;
        } else if (x < 20) {
            return 1;
        } else {
            return 2;
        }
    }

    function ternary(uint _x) public pure returns (uint) {
        if (_x < 10) {
            return 1;
        }
        return 2;

        // shorthand way to write if / else statement
        // the "?" operator is called the ternary operator
        // return _x < 10 ? 1 : 2;
    }
}