number-counter/src/static-delay.txt

Number Counter is package for count number upward and downward.

import React from 'react';

export const MakeButton = props => {
  const { text, marginTop, onClick, className } = props;
  return (
    <button style={{ marginTop: marginTop }} onClick={onClick} className={className}>{text}</button>
  );
}

export class Increment extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      countedValue: props.start,
    }
    this.countUp = this.countUp.bind(this);
  }

  componentDidMount() {
    const { start, end, delay } = this.props;
    const totalCount = end - (start || 0) + 1;
    const newDelay = (delay * 1000) / totalCount;
    const newStartPoint = (end * 95) / 100;
    this.countUp(start || 0, end, newDelay, Math.floor(newStartPoint));
  }

  countUp(start, end, delay, newStartPoint) {
    let newDelay = delay;
    let staticDelay = 100;
    if (newStartPoint === start) {
      newDelay += staticDelay;
      staticDelay += 300;
      newStartPoint = (end * 99) / 100;
    }
    if (start !== end) {
      start++;
      setTimeout(
        () => this.setState({ countedValue: start }, () => this.countUp(start, end, newDelay, newStartPoint))
        , delay);
    }
  }
  render() {
    const { countedValue } = this.state;
    const { className } = this.props;
    return (
      <div className={className}>{countedValue}</div>
    )
  }
}