Swift Language Reading & Writing JSON JSON Parsing Swift 3
Example
Here is the JSON File we will be using called animals.json
{
"Sea Animals": [
{
"name": "Fish",
"question": "How many species of fish are there?" },
{
"name": "Sharks",
"question": "How long do sharks live?"
},
{
"name": "Squid",
"question": "Do squids have brains?"
},
{
"name": "Octopus",
"question": "How big do octopus get?"
},
{
"name": "Star Fish",
"question": "How long do star fish live?"
}
],
"mammals": [
{
"name": "Dog",
"question": "How long do dogs live?"
},
{
"name": "Elephant",
"question": "How much do baby elephants weigh?"
},
{
"name": "Cats",
"question": "Do cats really have 9 lives?"
},
{
"name": "Tigers",
"question": "Where do tigers live?"
},
{
"name": "Pandas",
"question": "WHat do pandas eat?"
} ] }
Import your JSON File in your project
You can perform this simple function to print out your JSON file
func jsonParsingMethod() {
//get the file
let filePath = Bundle.main.path(forResource: "animals", ofType: "json")
let content = try! String(contentsOfFile: filePath!)
let data: Data = content.data(using: String.Encoding.utf8)!
let json: NSDictionary = try! JSONSerialization.jsonObject(with: data as Data, options:.mutableContainers) as! NSDictionary
//Call which part of the file you'd like to pare
if let results = json["mammals"] as? [[String: AnyObject]] {
for res in results {
//this will print out the names of the mammals from out file.
if let rates = res["name"] as? String {
print(rates)
}
}
}
}
If you want to put it in a table view, I would create a dictionary first with an NSObject.
Create a new swift file called ParsingObject and create your string variables.
Make sure that the variable name is the same as the JSON File
. For example, in our project we have name and question so in our new swift file, we will use
var name: String?
var question: String?
Initialize the NSObject we made back into our ViewController.swift var array = ParsingObject Then we would perform the same method we had before with a minor modification.
func jsonParsingMethod() {
//get the file
let filePath = Bundle.main.path(forResource: "animals", ofType: "json")
let content = try! String(contentsOfFile: filePath!)
let data: Data = content.data(using: String.Encoding.utf8)!
let json: NSDictionary = try! JSONSerialization.jsonObject(with: data as Data, options:.mutableContainers) as! NSDictionary
//This time let's get Sea Animals
let results = json["Sea Animals"] as? [[String: AnyObject]]
//Get all the stuff using a for-loop
for i in 0 ..< results!.count {
//get the value
let dict = results?[i]
let resultsArray = ParsingObject()
//append the value to our NSObject file
resultsArray.setValuesForKeys(dict!)
array.append(resultsArray)
}
}
Then we show it in our tableview by doing this,
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return array.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
//This is where our values are stored
let object = array[indexPath.row]
cell.textLabel?.text = object.name
cell.detailTextLabel?.text = object.question
return cell
}
