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Practice refactoring with ES2015 features.

CodeRoad is an open-sourced interactive tutorial platform for the Atom Editor. Learn more atCodeRoad.io.

• install the tutorial package

  npm install --save coderoad-es2015

• install and run theatom-coderoad plugin

let allows you to declare variables that are limited in scope to the block, statement, or expression on which it is used.

This is unlike thevar keyword, which defines a variable globally, or locally to an entire function regardless of block scope.

varglobal=true;letblockScoped=true;

const is block-scoped, much likelet statement.

However, the value of a constant cannot change through re-assignment, and it can't be redeclared.

constname='Shawn';name='Ben';// Uncaught TypeErrorconsole.log(name);// Shawn

Note: Atom uses an older version of Chrome that does not fully implement const yet. Const will work in Atom after a few months.

An arrow function (=>) expression has a shorter syntax compared to function expressions and lexically binds thethis value.

Arrow functions are always anonymous.

// multi-lineconstadd=(x,y)=>{returnx+y;};// single line, auto returnsconstsubtractOne=x=>x-1;constgetOne=()=>1;

Template literals are string literals allowing embedded expressions. You can use multi-line strings and string interpolation features with them.

Template strings are wrapped in the backtick symbol: '`'. Variables can be put inside of template strings using${ name } syntax.

letsingle=`string text`;letmulti=`string text line 1 string text line 2`;lettemplate=`string text${expression} string text`;

A shorthand for writing objects.

constfoo='something';constbar='else';// using object literal shorthandconstfooObj={  foo, bar};// { foo: 'something', bar: 'else'}