无需转译器即可将 ES6 JavaScript 转换为 ES5

Question

我不熟悉新的 JavaScript ES6 编码约定，并且在我需要它是普通的旧 JavaScript ES5 的地方已经给出了一些代码。

我需要在不使用 Babel 或任何其他转译器的情况下转换此 JS 代码。 我不能使用 Babel，因为我不允许在工作中使用它。

我意识到所有的“const”都可以转换为“var”，但不确定新的箭头函数和其他项目。

我试过转换但得到：

未捕获的 ReferenceError：未定义行

我想转换为 ES5 的 ES6 代码是：

const data = [{ "rec": "1", "region": "LEFT", "intrface": "Line-1" },{ "rec": "1", "region": "LEFT", "intrface": "Line-2" },{ "rec": "1", "region": "RIGHT", "intrface": "Line-3" },{ "rec": "1", "region": "RIGHT", "intrface": "Line-4" }];

const s = Snap("#svg");
const height = 40;
const canvasWidth = 400;
const lineWidth = 180;
const rightOffset = canvasWidth/2 - lineWidth;

const leftLines = data.filter((line) => !isRightLine(line));
const rightLines = data.filter(isRightLine);

leftLines.forEach(drawLine);
rightLines.forEach(drawLine);

const numberOfLines = Math.max(leftLines.length, rightLines.length);
const rectSize = 20;
const rectangles = [];

for (let i = 0; i < numberOfLines; i++) {
    rectangles.push(drawRect(i));
}

function drawLine(data, index) {
    const {intrface} = data;
    const isRight = isRightLine(data);
    const x = isRight ? canvasWidth/2 + rightOffset : 0;
  const y = height * (index + 1);
  const stroke = isRight ? 'red' : 'black';

    const line = s.line(x, y, x + 180, y);
  line.attr({
    stroke,
    strokeWidth: 1
  });

  const text = s.text(x + 10, y - 5, intrface);

  text.attr({
    fill: stroke,
    cursor: 'pointer'
  });

  text.click(() => {
    console.log('clicked', data);

    //window.location.href = "http://stackoverflow.com/";
  });
}

function isRightLine({region}) {
    return region === 'RIGHT';
}

function drawRect(index) {
    const x = canvasWidth/2 - rectSize/2;
  const y = height * (index + 1) - rectSize/2;
    const rectangle = s.rect(x, y, rectSize, rectSize);

  rectangle.attr({
    fill: 'black'
  });

  console.log('rr', x, y);

  return rectangle;
}

Answer 1

我假设您对 es6 不是很熟悉，因此您可能对babeljs.io不太熟悉，它为您提供了转换回来的选项：

检查这个链接。

"use strict";

var data = [{ "rec": "1", "region": "LEFT", "intrface": "Line-1" }, { "rec": "1", "region": "LEFT", "intrface": "Line-2" }, { "rec": "1", "region": "RIGHT", "intrface": "Line-3" }, { "rec": "1", "region": "RIGHT", "intrface": "Line-4" }];

var s = Snap("#svg");
var height = 40;
var canvasWidth = 400;
var lineWidth = 180;
var rightOffset = canvasWidth / 2 - lineWidth;

var leftLines = data.filter(function (line) {
  return !isRightLine(line);
});
var rightLines = data.filter(isRightLine);

leftLines.forEach(drawLine);
rightLines.forEach(drawLine);

var numberOfLines = Math.max(leftLines.length, rightLines.length);
var rectSize = 20;
var rectangles = [];

for (var i = 0; i < numberOfLines; i++) {
  rectangles.push(drawRect(i));
}

function drawLine(data, index) {
  var intrface = data.intrface;

  var isRight = isRightLine(data);
  var x = isRight ? canvasWidth / 2 + rightOffset : 0;
  var y = height * (index + 1);
  var stroke = isRight ? 'red' : 'black';

  var line = s.line(x, y, x + 180, y);
  line.attr({
    stroke: stroke,
    strokeWidth: 1
  });

  var text = s.text(x + 10, y - 5, intrface);

  text.attr({
    fill: stroke,
    cursor: 'pointer'
  });

  text.click(function () {
    console.log('clicked', data);

    //window.location.href = "http://stackoverflow.com/";
  });
}

// you might want to change this - howeverever you will have to change everywhere in the code that calls isRightLine to pass a primitive vs an object.
function isRightLine(_ref) {
  var region = _ref.region;

  return region === 'RIGHT';
}

function drawRect(index) {
  var x = canvasWidth / 2 - rectSize / 2;
  var y = height * (index + 1) - rectSize / 2;
  var rectangle = s.rect(x, y, rectSize, rectSize);

  rectangle.attr({
    fill: 'black'
  });

  console.log('rr', x, y);

  return rectangle;
}