$your_array= [['name'=>'и','country'=>'ч','year'=>'x'],['name'=>'qwer','country'=>'fergr','year'=>'0'],['name'=>'gtrh','country'=>'rthttyh','year'=>'1'],['name'=>'23rty','country'=>'wefrt','year'=>'x'],['name'=>'qwefg','country'=>'wertyuj','year'=>'x']];
foreach($your_array as $element) {
$hash = $element['year'];
$unique_array[$hash] = $element;
}
print_r($unique_array); <ul id=menu>
<li> text1</li>
<li> text2</li>
<li> text3</li>
<li> text4</li>
<li> text5</li>
<li> text6</li>
</ul>
<script>
var menu= document.getElementById('menu');
menu.onclick= function(e) {
[].forEach.call(menu.querySelectorAll('li'), function(i) {
i.classList.remove('active');
});
e.target.classList.add('active');
console.log(e.target);
}
</script> getElementById('id').innerHTML= ответ сервера.