JSFiddle - React, Tailwind, and code Playground

JavaScript

items = [
  {market_hash_name: "item_1"}, 
  {market_hash_name: "item_2"}, 
  {market_hash_name: "item_3"}, 
  {market_hash_name: "item_4"},
  {market_hash_name: "item_3"},
  {market_hash_name: "item_4"}
];

g_ItemName = ["item_1", "item_4", "item_5", "item_4", "item_4"];
var otvet = null; 
var new_items2 = items;
var new_items = items;

for(var j = 0; j < g_ItemName.length; j++){
var sendItemName = g_ItemName[j];
console.log('sendItemName : ', sendItemName);
if (typeof sendItemName != 'undefined') {
	if (innova(sendItemName, new_items)) {
		document.write('Вещь "'+sendItemName+'" найдена в инвентаре<br>');
		otvet = true;
	}
	else{	
		document.write('Вещь "'+sendItemName+'" не найдена в инвентаре<br>');
		otvet = false;
	}
	document.write("Длина массива для поиска: " + new_items.length + "<br>");
}
}      	 

				function innova(name_sends, new_items) {
	for(var a = 0; a < new_items.length; a++){
    ft = new_items;
		if (name_sends === new_items[a].market_hash_name) {
			new_items.splice(a, 1);
			return true;
		}
	}
	return false;
}

for(var i = 0; i < new_items2.length; i++){					   
              document.write('items market_hash_name: '+new_items2[i].market_hash_name+'<br>');
		    }