HarmonyOS 浮点数如何保留1位小数

@Entry 
@Component 
struct Index { 
  aboutToAppear(): void { 
    console.log(this.toOneDecimalPlace(1.33333)) 
  } 
  build() { 
  } 
 
  toOneDecimalPlace(num: number): string { 
    return num.toFixed(1); 
  } 
}

toOneDecimalPlace(num: number): string { 
  const arr = num.toString().split('.') 
  return arr[0] + '.' + arr[1].substring(0,1); 
}