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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

Usinglet &const.

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`;