Does `try catch` block makes partial changes in state variable in case of error in solidity

Question

If we consider this code below

pragma solidity 0.8.0;
interface testInterface{
   function externalFunction(uint _test) external returns(bool);
}

contract abc{
    uint public var1;

    function testTryCatch() public {
        var1 = 22;
        try testInterface(address(0)).externalFunction(var1) {} catch {}
    }
}

it is sure function call will fail on try line , when call will finish value of var1 will be 22 or 0 ? if 0 then what is use of try catch and differences from other language if 22 then is it not violating the concept of blockchain ?

Answer 1

I did a test run to check the effect and transaction failed (hence no value updated in storage) even with try catch block