I don't understand the behavior of react's setState.


                {this.state.count}
                <button onClick={this.add}>click</button>
            </div>
        );
    }
}

export default App;

according to official documents, repeating setState count: this.state.count + 1 is only added once

but this problem does not exist with count: PPthis.state.count.

can someone tell me what"s going on

Javascript react.js
Sep.10,2021
React doesn't update this.state.count until the component is re-rendered

so every time this.setState ({count: this.state.count + 1}) is executed, this.state.count is 0, and the final result of setState is 1; while this.setState ({count: PPthis.state.count}) each time this.state.count increases by + 1, and the final result of setState is the result of this.state.count . 

PPthis.state.count

this code is equivalent to 

this.state.count = this.state.count + 1

Previous: The problem of multiple versions of php calling each other using exec

Next: How to solve the problem that the webpage response is too slow due to multiple ifream loading on the webcast page?

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
© 2021 CodesHelper
Advertising Contact us About us
Menu