PHP，Xcode 8，Swift 3 - 如何将数组从Web服务器返回到Xcode模拟器

Question

I can read text from a web server and print it to the Xcode uilabel, but I don't know how to parse a returning array. I am trying to get a and b from the server, add them, and print to uilabel using Swift 3.

This is the PHP and Xcode 8:

connect-add.php

<?php
$a=3;
$b=5;
$data=array($a,$b);
echo json_encode($data);
?>

Xcode 8

import UIKit
import Foundation

class ViewController: UIViewController {

var a=0
var b=0
var c=0


@IBOutlet weak var result: UILabel!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a 
nib.
}

@IBAction func getVars(_ sender: AnyObject) {

    // set label during request

    self.result.text="WAITING"

    // send request to connect-add.php and retrieve a and b

    let myUrl = NSURL(string: "http://www.example.com/connect-add.php")

    var request = URLRequest(url:URL(string: 
"http://www.example.com/connect-add.php")!)

    request.httpMethod = "POST"

    let postString = ""

    request.httpBody = postString.data(using: .utf8);

    let task = URLSession.shared.dataTask(with: request) {
        data, response, error in

        if error != nil
        {
            print("error=\(error)")
            return
        }

        // receive response to connect-add and parse to a and b

        var response = String(data: data!, encoding: .utf8)

        var a=response[0]
        var b=response[1]

        // add a and b and display

        var c=a+b
        self.result.text=c
    }
    task.resume()

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}
}

Xcode gives me an error for setting var a=response[0] and for setting var b=response[1]. Any ideas?

I have editted PHP and Xcode to add JSON Serialization parsing. Xcode is showing one error--Use of unresolved identifier "JSON". Here is the code.

PHP

<?php
$a=3;
$b=5;
$data="a1=".$a.", b1=".$b;
echo json_encode($data);
?>

Xcode 8

import UIKit
import Foundation

class ViewController: UIViewController {

var a=0
var b=0
var c=0


@IBOutlet weak var result: UILabel!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a 
nib.
}

@IBAction func getVars(_ sender: AnyObject) {

    // set label during request

    self.result.text="WAITING"

    // send request to connect-add.php and retrieve a and b

    let myUrl = NSURL(string: "http://www.example.com/connect-add.php")

    var request = URLRequest(url:URL(string: 
"http://www.example.com/connect-add.php")!)

    request.httpMethod = "POST"

    let postString = ""

    request.httpBody = postString.data(using: .utf8);

    let task = URLSession.shared.dataTask(with: request) {
        data, response, error in

        if error != nil
        {
            print("error=\(error)")
            return
        }

        // receive response to connect and parse to a and b

        var response = String(data: data!, encoding: .utf8)

        var obj=JSON.parse(response)

        var a=obj.a1
        var b=obj.b1

        // add a and b and display

        var c=a+b
        self.result.text=c
    }
    task.resume()

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}
}

Answer 1

if var json = try JSONSerialization.jsonObject(with: data) as? [String: 
String], var a2 = json["a"], var b2 = json["b"] {
// It's working

}