CODEWITHSUNDEEP
reactjsreact-native
salmanaacvf
salmanaacvf

Reputation: 257

react native why there is a time lag in setState function?

I have a checkbox that calling two functions on on press event , in the first function I am changing the state of the component , on the second function I am calling that state to see if it has been changed by the first function, by displaying the state of that component by console.log I see that changes are displayed only after second click on the checkbox , so first click empty data displayed , seconde click data and changes are displayed on the console , would you please help me understand why there is that time lag ?

this is my code :

<CheckBox  onPress={() => {this.treggerCheckBoxcallback(item); this.editeTask()}} />

//function 1
  treggerCheckBoxcallback = tsk => {
    let currentTasks = tsk;
  this.setState({ currentTask : currentTasks});
      };

// function 2
   editeTask = () => {
    console.log(this.state.currentTask);
    }

Upvotes: 1

Views: 1373

Answers (1)

Poptocrack
Poptocrack

Reputation: 3009

the function setState is asynchronous, so your console log shows the state right before the setState is really called. To avoid such behavior you can use setState like this:

this.setState({ data: yourData }, () => {
  console.log(this.state.data)
  // code called after the setState is finished. (callback)
})

Upvotes: 3

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