How to show the 5 latest laps output-CodePudding

I'm new on react-native. I'm trying to make the lap button on my stopwatch to show 5 latest result. Here is my code:

laps() {
return this.state.laps.map(function(time, index) {
  return <View key={index} style={styles.lap}>
    <Text style={styles.lapText}>
      Lap #{index   1}
    </Text>
    <Text style={styles.lapText}>
      {formatTime(time)}
    </Text>
  </View>
});}


handleLapPress() {
var lap = this.state.timeElapsed;
if(this.state.running){
  this.setState({
  startTime: new Date(),
  laps: this.state.laps.concat([lap])
});
}
else{
  this.setState({
  startTime: new Date(),
  laps: this.setState.laps=[]
});
}}

For now, when I hit on the lap button. It show the lap time but when there are more than 5 laps. The latest one was disappear. So, what should I do to make my stopwatch show 5 latest.

CodePudding user response：

use last_five_laps as your new array to show last 5 laps

let last_five_laps = this.state.laps.slice(-5);