Objective-C execute Javascript

ViewController.m

//
//  ViewController.m
//  app-with-jscontext
//
//  Created by DE505 on 21/05/2018.
//  Copyright © 2018 DE505. All rights reserved.
//

#import "ViewController.h"

@import JavaScriptCore;

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    // getting a JSContext
    JSContext *context = [JSContext new];
    
    context[@"consoleLog"] = ^(NSString *message) {
        NSLog(@"Javascript Log: %@", message);
    };
    
    // enable exception handling
    [context setExceptionHandler:^(JSContext *context, JSValue *value) {
        NSLog(@"%@", value);
    }];
    
    NSString *myScript = @"var result = 0;"
    " consoleLog('Hello world');"
    " function a() { return Promise.resolve(39); }"
    " function b() { return Promise.resolve(1); }"
    " a().then((r) => consoleLog(r.toString()));";
    
    [context evaluateScript:myScript];
    
    JSValue *result = context[@"result"];
    NSLog(@"%@", result);
    
    NSString *phone = @"71 878782782";
    // defining a JavaScript function
    NSString *jsFunctionText =
    @"var isValidNumber = function(phone) {"
    "    var phonePattern = /^[0-9]{3}[ ][0-9]{3}[-][0-9]{4}$/;"
    "    return phone.match(phonePattern) ? true : false;"
    "}";
    [context evaluateScript:jsFunctionText];
    
    // calling a JavaScript function
    JSValue *jsFunction = context[@"isValidNumber"];
    
    JSValue *value = [jsFunction callWithArguments:@[ phone ]];
    
    NSLog(@"%@", value);
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


@end