javascript - IndexedDB 中的算术运算

Question

我需要你的帮助。我正在做我的大学作业。我正在研究 IndexedDB。我想对来 self 的 indexedDB 作为对象的数据进行一些加法、减法。我正在从 IndexedDB 检索值并将其保存以供将来应用算术运算时使用。

当我对数据求和时，它会连接数字。

For Example:

total += price[index].name; //in price array there is data like 100,50,20 my output should be sum of these values. but i am getting the output like this "1005020"

我不知道如何添加这些数据。这是我的代码。

function GetData(){
	var output = document.getElementById("printOutput");
					var product=[];
					var price=[];
					var person=[];
					var index=0;
					var total = 0;
                    var transaction = db.transaction("accounts", IDBTransaction.READ_WRITE);
                    var objectStore = transaction.objectStore("accounts");
 
                    var request = objectStore.openCursor();
                    request.onsuccess = function(evt) {  
                    
					var cursor = evt.target.result;  
                        
                            if(cursor)
							{
								product.push({name: cursor.value.pType});
								price.push({name: cursor.value.pPrice});
								person.push({name: cursor.value.personID});
								cursor.continue();
							}
                    while(product.length!=index)
					{
						if(person[index].name==1){
						var element = document.createElement("p");
						element.textContent = product[index].name+"\t"+price[index].name;
						output.appendChild(element);
						total = total + price[index].name;
						}
						index++;
					}
					var sum = document.createElement("p");
					sum.textContent = "Total Amount = " + total;
					output.appendChild(sum);					
	
                    };}

Answer 1

对于以后访问的人，通过评论解决，以下是解决方案:

Typically data is retrieved from IDB in form of String object, so your "+" operator is concatenating instead of adding. So, first convert your Strings into number and then perform addition. For conversion please refer here