Dammmien

// if no duplicate in the first list
a1.concat( a2.filter( i => a1.indexOf( i ) === -1 ) );


// if duplicate in the first list
a1.concat( a2 ).reduce( function( p, c, i, a ) {
    if ( p.indexOf( c ) === -1 ) p.push( c );
    return p;
}, [] );

Dammmien

function shuffle( a ) {
    var m = a.length, t, i;

    while ( m ) {
        i = Math.floor( Math.random() * m-- );
        t = a[ m ];
        a[ m ] = a[ i ];
        a[ i ] = t;
    }

Dammmien

"abcdefghijklmnopqrstuvwxyz".match( /.{1,4}/g );

// [ "abcd", "efgh", "ijkl", "mnop", "qrst", "uvwx", "yz" ]

Dammmien

let partition = ( a, n ) => a.length ? [ a.splice( 0, n ), ...partition( a, n ) ] : [];

partition( [ 1, 2, 3, 4, 5, 6, 7, 8 ], 2 );

// [
//     [ 1, 2 ],
//     [ 3, 4 ],
//     [ 5, 6 ],
//     [ 7, 8 ]
// ]

Dammmien

var matrix = [],
    H = 4, // 4 rows
    W = 6; // of 6 cells

for ( var y = 0; y < H; y++ ) {
    matrix[ y ] = [];
    for ( var x = 0; x < W; x++ ) {
        matrix[ y ][ x ] = "foo";
    }
}

Dammmien

var average = arr => arr.reduce( ( p, c ) => p + c, 0 ) / arr.length;

average( [ 1, 2, 3, 4, 5, 6, 7, 8, 9 ] );

// 5

Dammmien

var nodes = [
    {
        links: [ 1 ], // node 0 is linked to node 1
        visited: false
    }, {
        links: [ 0, 2 ], // node 1 is linked to node 0 and 2
        path: [],
        visited: false
    },
    ...

Dammmien

class TimeTracker {

    constructor() {
        this.timers = {};
    }

    logLoadTimes() {
        var loadTimes = chrome.loadTimes();
        console.log( `commitLoadTime .............. ${( loadTimes.commitLoadTime - loadTimes.startLoadTime ).toFixed( 2 )}s` );
        console.log( `finishDocumentLoadTime ...... ${( loadTimes.finishDocumentLoadTime - loadTimes.startLoadTime ).toFixed( 2 )}s` );

Dammmien

(function() {
    console.clear();
    var loadTimes = chrome.loadTimes();
    console.log( "requestTime................. " + ( loadTimes.startLoadTime - loadTimes.requestTime ).toFixed( 2 ) + 's' );
    console.log( "commitLoadTime.............. " + ( loadTimes.commitLoadTime - loadTimes.startLoadTime ).toFixed( 2 ) + 's' );
    console.log( "finishDocumentLoadTime...... " + ( loadTimes.finishDocumentLoadTime - loadTimes.startLoadTime ).toFixed( 2 ) + 's' );
    console.log( "finishLoadTime.............. " + ( loadTimes.finishLoadTime - loadTimes.startLoadTime ).toFixed( 2 ) + 's' );
})()

Dammmien

var SD = {

    create: function( tag, attrs ) {
        tag = document.createElement( tag );
        for ( var attr in attrs ) tag[ attr ] = attrs[ attr ];
        return tag;
    },

    get: function( selector, context, undefined ) {
        var matches = {