alex

$('.plus-minus').on('click', e => $('.quantity-input', e.currentTarget).val((i, val) => {
	if (e.target === $('.minus', e.currentTarget)[0]) return val <= 0 ? val : --val;
  if (e.target === $('.plus', e.currentTarget)[0]) return ++val;
}));

document.querySelector('#sidebar').onwheel = e => e.stopPropagation();

jQuery('#carousel_android').flexslider({...}); // неправильно
jQuery('.flexslider').flexslider({...}); // правильно

const someSrt = "954  432 534  test abc test test test abc test test abc ";

const words = someSrt.match(/([a-zA-Z]+)/g);
const numbers = someSrt.match(/(\d+)/g);

console.log(words); // ["test", "abc", "test", "test", "test", "abc", "test", "test", "abc"]
console.log(numbers); // ["954", "432", "534"]

const HTMLstring = `
<div>
	<div class="wanted"></div>
	<div>
		<div class="wanted"></div>
	</div>
</div>
<div class="wanted"></div>
<div>
	<div></div>
	<div></div>
	<div class="wanted"></div>
</div>`;

$('.wanted', $.parseHTML(`<root>${HTMLstring}</root>`)); // jQuery collection

<table class="table-1">
  <tr class="row-1">
    <td><span class="name">Test</span></td>
    <td><button>Get</button></td>
  </tr>
  <tr class="row-999">
    <td><span class="name">Test 999</span></td>
    <td><button>Get</button></td>
  </tr>
<table>

$('.table-1').on('click', 'button', e => {
	const text = $(e.target).closest('tr').find('span.name').text();
  console.log(text);
});

<btn-default @click.native="showModal = true">Заказать</btn-default>

var SomeObject = function() {
  this.prop = 'any';
  this.filters = Object.assign({}, this.constructor.filters);
}

SomeObject.filters = SomeObject.prototype.filters = {};
SomeObject.addFilter = SomeObject.prototype.addFilter = function(n){
  this.filters[n] = function(){
    console.log(n);
  }
};

SomeObject.addFilter('a');
SomeObject.addFilter('b');

var Instance1 = new SomeObject();
var Instance2 = new SomeObject();

Instance1.addFilter('c');

console.log(Instance1.filters.a()); // 'a'
console.log(Instance2.filters.a()); // 'a'

console.log(Instance1.filters.b()); // 'b'
console.log(Instance2.filters.b()); // 'b'

console.log(Instance1.filters.c()); // 'c'
console.log(Instance2.filters.c()); // TypeError: Instance2.filters.c is not a function

const ex = "My favourite game";
    
function wordReverse(str) {
    var newStr = '',
        strLength = str.length;
      for (var i = 0; i < strLength; i++) {
        newStr += str[strLength - 1 - i];
    }  
    return newStr;
}

function wordsReverse(str) {
    str += " ";
    var wordsReverseArray = [],
        wordStr = "";
    for(var i=0; i<str.length; i++) {
        if(str[i] !== " ") {
            wordStr += str[i];
        } else {
            wordsReverseArray.push(wordReverse(wordStr));
            wordStr = "";
        }
    }
    return wordsReverseArray.join(' ');
}

console.log(wordsReverse(ex)); // "yM etiruovaf emag"

span {
	background-image: linear-gradient(to right, red, red), linear-gradient(to left, red, red);
	background-size: 0 2px;
	background-position: bottom left, bottom right;
	background-repeat: no-repeat;
	transition: background-size .2s ease-in-out;
}

span:hover {
	background-size: calc(50% - 2px) 2px;
}