CoffeeScript to ES6 cheatsheet

References:

• https://gist.github.com/danielgtaylor/0b60c2ed1f069f118562

• https://robots.thoughtbot.com/replace-coffeescript-with-es6

Iteration

• On object properties:

// coffee
for prop, value of obj

// ES6
_.each(obj, (value, key)=>{
});

// or (NOTE don't use it for array)
for (let prop in obj) {
}

• On collection (array):

// coffee
for ele in arr
    console.log ele

// es6
for (let ele of arr) {
    console.log(ele);
}

// or
arr.forEach( (ele) => {
    console.log(ele);
    //  函数体内的this对象，就是定义时所在的对象，而不是使用时所在的对象
});

// or
arr.forEach(function(ele){
    console.log(ele);
    //  this is the function
});

Misc

• Replace ==/!= with ===/!==

• There is no concept of class variable in ES6, you might want to just turn that to a static method:

// coffee
class MyFile
    @EXT = '.myfile'

// es6
class MyFile {
  static Ext() {
    return '.myfile';
  }
}