hzzzzl

if ( new Set([a, b, c]).size === 1 ) {  // сколько угодно переменных в массиве
            this.returnItemBoolian();
 }

// make sure it doesn't count my own properties
(function () {
    var results, currentWindow,
    // create an iframe and append to body to load a clean window object
    iframe = document.createElement('iframe');
    iframe.style.display = 'none';
    document.body.appendChild(iframe);
    // get the current list of properties on window
    currentWindow = Object.getOwnPropertyNames(window);
    // filter the list against the properties that exist in the clean window
    results = currentWindow.filter(function(prop) {
        return !iframe.contentWindow.hasOwnProperty(prop);
    });
    // log an array of properties that are different
    console.log(results);
    document.body.removeChild(iframe);
}());

Number.prototype.isOdd = function() { return this % 2 === 1 }

class Express {
	response = {}
	middles = []

	use = func => this.middles.push(func)

	get = () => {
		this.middles.forEach(func => func(this.response))
		console.log('RESPONSE NOW: ',this.response)
	}
}

app = new Express()
app.get()
// response: {}

function addBla(res) { res.bla = 17 }
// миддлвар добавляет какое-то свойство в response от сервера

app.use(addBla)
app.get()
// response: {bla: 17}

const list = [
  [1,2,3,4,5],
  [2,3,4,5,6],
  [3,4,5,6,7],
  [4,5,6,7,8],
  ['adasd', 123, 312, 1234]
];

const remove = [
  [2,3,4,5,6],
  [3,4,5,6,7],
  [4,5,6,7,8],
]

_remove = remove.map(a => a.toString())
list.filter(a => !_remove.includes(a.toString()))

Array.prototype.myUnshift = function(...args) { 
  return [...this, ...args]
}

[3,5].myUnshift(34,52,25)
// [3, 5, 34, 52, 25]

data = [
        {
            id: 1,
            title: 'NubeUnique',
            description: 'Description of NubeUnique project',
            content: '<span>Test<span> content for work item'
        },
        {
            id: 2,
            title: 'Performance',
            description: 'Description of Performance project',
            content: '<span>Test<span> content for work item'
        },
        {
            id: 3,
            title: 'Tabu',
            description: 'Description of Tabu project',
            content: '<span>Test<span> content for work item'
        }
    ];

data.find(d => d.id === 2) 
// {id: 2, title: "Performance", description: "Description of Performance project", content: "<span>Test<span> content for work item"}

html = ''

for (key in result.category) {
	html += `<p>${key}</p><select>`

	for (key1 in result.category[key].family) {
		html += `<option>${key1}</option>`
    }

	html += `</select>`
}