Why we have same function in onPress react native-CodePudding

I'm learning react-native, as a beginner, i learn by search random project on github and find what weird and not understand, then learn from it, today i see some code of a dude ( i don't remember his name) but it looke like this

 {isTrue && (
          <TouchableOpacity onPress={reset && reset}>  ===>they are the same function
            <Text>Reset</Text>
          </TouchableOpacity>
  )}

Why we have something like this? Why don't use reset directly, this guy use &&

Please help me on this, i'm so confuse about this

CodePudding user response：

I expect the code rather looks like that:

  <TouchableOpacity onPress={() => {reset && reset()}}>
    <Text>Reset</Text>
  </TouchableOpacity>

reset && reset() // && shorthand for

if(reset) {
 reset()
}

AFAIK there a no relevant different between

  <TouchableOpacity onPress={reset && reset}}>
    <Text>Reset</Text>
  </TouchableOpacity>

and

  <TouchableOpacity onPress={reset}}>
    <Text>Reset</Text>
  </TouchableOpacity>

reset && reset will ensure that reset is always undefined when reset is falsy. Otherwise reset could be false,0,'', null or NaN.

But i think that has no effect but meet the TypeScript definition onPress definition which is undefined or function onPress?: () => void;