我正在尝试使用JavaScript按照最大值对数组值进行排序，但是给我错误的结果。这是我的代码：
import UIKit
struct Product {
var price = 0
}
class TicketBookingVC: UIViewController , UITableViewDelegate, UITableViewDataSource {
@IBOutlet weak var tblView: UITableView!
@IBOutlet weak var mainTblView: UIView!
var bookingDetails = NSDictionary()
var paymentDetails = NSDictionary()
var arrPaymentDetails = NSArray()
var productArray = [Product]()
var product : Product!
private var counterValue = 1
var productIndex = 0
var counterLbl = UILabel()
@IBOutlet weak var bookBtn: UIButton!
@IBOutlet weak var eventImg: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
tblView.delegate = self
tblView.dataSource = self
let payment = self.paymentDetails.value(forKey: "payment") as! NSArray
self.arrPaymentDetails = payment as NSArray
for _ in 0...10{
productArray.append(Product(price: 1))
}
// Do any additional setup after loading the view.
}
func numberOfSections(in tableView: UITableView) -> Int {
return 3
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if section == 0 {
return 1
}
else if section == 1{
return arrPaymentDetails.count
}
else{
return 1
}
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.section == 0 {
let cell = tableView.dequeueReusableCell(withIdentifier: "cellfirst", for: indexPath)
cell.selectionStyle = .none
return cell
}
else if indexPath.section == 1 {
let cell = tableView.dequeueReusableCell(withIdentifier: "cellsecond", for: indexPath)
let mainViewCell = cell.contentView.viewWithTag(2000) as! UIView
let normalView = cell.contentView.viewWithTag(2001) as! UIView
let eventName = cell.contentView.viewWithTag(2003) as! UILabel
let eventPrice = cell.contentView.viewWithTag(2004) as! UILabel
counterLbl = cell.contentView.viewWithTag(2007) as! UILabel
let decrementBtn = cell.contentView.viewWithTag(2005) as! UIButton
let incrementBtn = cell.contentView.viewWithTag(2006) as! UIButton
let dictAllDetails = self.arrPaymentDetails.object(at: indexPath.row) as! NSDictionary
print("dictallgroups : \(dictAllDetails)")
if dictAllDetails.value(forKey: "label") != nil {
eventName.text = dictAllDetails.value(forKey: "label") as! String
}
else{
eventName.text = ""
}
if dictAllDetails.value(forKey: "price") != nil {
eventPrice.text = "₹ \(dictAllDetails.value(forKey: "price") as! String)"
}
else{
eventPrice.text = "₹ 0"
}
decrementBtn.addTarget(self, action:#selector(self.decrementbuttonClicked), for: .touchUpInside)
incrementBtn.addTarget(self, action:#selector(self.incrementbuttonClicked), for: .touchUpInside)
product = productArray[indexPath.row]
counterLbl.text = "\(product.price)"
productIndex = indexPath.row
cell.selectionStyle = .none
return cell
}
else {
let cell = tableView.dequeueReusableCell(withIdentifier: "cellthird", for: indexPath)
cell.selectionStyle = .none
return cell
}
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
if indexPath.section == 0{
return UITableView.automaticDimension
}
else{
return 80
//return UITableView.automaticDimension
}
}
@objc func decrementbuttonClicked() {
print("Button decrement")
if(counterValue != 1){
counterValue -= 1;
}
print("\(counterValue)")
self.counterLbl.text = "\(counterValue)"
product.price = counterValue
print("\(product.price)")
addProductToCart(product: product, atindex: productIndex)
}
@objc func incrementbuttonClicked() {
print("Button increment")
counterValue += 1;
print("\(counterValue)")
self.counterLbl.text = "\(counterValue)"
product.price = counterValue
print("\(product.price)")
addProductToCart(product: product, atindex: productIndex)
}
func addProductToCart(product: Product, atindex: Int) {
productArray[atindex] = product
calculateTotal()
}
func calculateTotal()
{
var totalValue = 0
for objProduct in productArray {
totalValue += objProduct.price
}
// self.totalLabel.text = "Total \(totalValue)"
}
在这里，我试图对值进行排序，例如function myFunction() {
var inputdata = [
[1001, 20],
[1002, 30],
[1001, 50],
[1003, 30],
[1002, 60],
[1003, 40],
[1001, 70]
];
var storedata = [];
for (var i = 0; i < inputdata.length; i++) {
if (i === 0) {
var data = {
'key': inputdata[i][0],
'value': inputdata[i][1]
};
storedata.push(data);
} else {
for (var j = 0; j < storedata.length; j++) {
if (storedata[j]['key'] == inputdata[i][0]) {
if (storedata[j]['value'] < inputdata[i][1]) {
storedata[j]['value'] = inputdata[i][1];
}
break;
} else {
var data = {
'key': inputdata[i][0],
'value': inputdata[i][1]
};
storedata.push(data);
}
}
}
}
console.log(storedata);
}
的最大值，但就我而言，预期结果没有到来。
答案 0 :(得分：1)
因为在您的内部循环中，当您再次使用j遍历数组时，一个条目可能已经是您要查找的条目，但是所有您要遍历的其他对象不是，对于那些您正在重复的条目。换句话说：将else {部分移出循环，首先检查整个数组是否存在该条目，并且仅在不添加新数组的情况下：
var exists = false;
for(var j = 0; j < storeddata.length; j++) {
if(/*...*/) {
// merge
exists = true;
break;
} // don't insert here
}
if(!exists) {
// insert
}
还不需要if(i === 0)部分（然后），因为storeddata将为空，因此它将直接进入if(!exists)部分并插入新条目。
我将其写为（确保您的方式也可以工作，并且可以如上所述进行修复）：
const result = [];
for(const [key, value] of inputdata) {
const duplicate = result.find(entry => entry.key === key);
if(duplicate) {
duplicate.value = Math.max(duplicate.value, value);
} else {
result.push({ key, value });
}
}
答案 1 :(得分：0)
尚不清楚是要按数组的第一个排序，然后按数组的第二个排序，还是要简单列出子数组的唯一值，第一个值仅在此处排序，还是需要从子数组的第一个值。
因此，我将提供所有它们（按子数组中的两个值排序），然后提供第二个ALL值，然后是子数组第一个元素的唯一值的第三个。
var inputdata = [
[1001, 20],
[1002, 30],
[1001, 50],
[1003, 30],
[1002, 60],
[1003, 40],
[1001, 70]
];
/* sort by the first and second values */
var sortedArray = inputdata.sort(function(a, b) {
if (a[0] == b[0]) {
return b[1] - a[1];
}
return b[0] - a[0];
}).reverse();
console.log(sortedArray);
/* just get the unique first values sorted */
let iA = [];
inputdata.forEach(function(element) {
iA.push(element[0]);
});
/* all first values, sorted */
console.log(iA.sort());
/* unique first values sorted */
let uniqueSorted = [...new Set(iA)].sort();
console.log(uniqueSorted);