Sending message to WhatsApp from your app using Swift?

Swift 5

Code

let urlWhats = "whatsapp://send?text=\("Hello World")"
if let urlString = urlWhats.addingPercentEncoding(withAllowedCharacters: NSCharacterSet.urlQueryAllowed) {
      if let whatsappURL = NSURL(string: urlString) {
            if UIApplication.shared.canOpenURL(whatsappURL as URL) {
                 UIApplication.shared.open(whatsappURL as URL)
             } 
             else {
                 print("please install watsapp")
             }
      }
}

 var url  = NSURL(string: "whatsapp://send?text=Hello%20Friends%2C%20Sharing%20some%20data%20here...%20!")

//Text which will be shared on WhatsApp is: "Hello Friends, Sharing some data here... !"

    if UIApplication.sharedApplication().canOpenURL(url!) {
        UIApplication.sharedApplication().open(url as URL, options: [:]) { (success) in
                if success {
                    print("WhatsApp accessed successfully")
                } else {
                    print("Error accessing WhatsApp")
                }
            }
    }

Note: text needs to be URL encoded. You can get it using any of the open source tools over internet or using addingPercentEncoding(withAllowedCharacters:) function in iOS. e.g.

var urlString = "Hello Friends, Sharing some data here... !"
var urlStringEncoded = urlString.addingPercentEncoding(withAllowedCharacters: NSCharacterSet.urlQueryAllowed)
var url  = NSURL(string: "whatsapp://send?text=\(urlStringEncoded!)")