当我运行我的程序时，我正在摆脱 memory 错误

Question

So, I actually wanna create a timer which will count back time, but when I'm running this script I'm always getting the 'Out of memory' error. Here is my onClick script:

handleClickStart = () => {
          while (this.state.hours > 0) {
              this.setState({
                  hours: this.state.hours - 1
              })
          } 
    }

Also I could show you the whole code if you'd need it

Answer 1

setState is asynchronous and it runs in batches, don't use setState inside a loop, rather create a new variable and set state at the end of the loop, like this

handleClickStart = () => {
    let hours = this.state.hours;
    while (hours > 0) {
        hours --;
    } 

    this.setState({hours});
}