// val, default empty value

    function verifyValue(val, defVal) {

        if((val == undefined) || (val == null)){

            return defVal;

        }

        return val;

    }

//Using Default Values

//Default values can be assigned

//to the variables just in case the value extracted from the array is undefined.

​

​

var[greeting = "hi",name = "Sarah"] = ["hello"];

​

    console.log(greeting);//"Hello"

    console.log(name);//"Sarah"

// app.module.ts

import { NgModule } from '@angular/core';

import { BrowserModule } from '@angular/platform-browser';

import { FormsModule } from '@angular/forms';

import { AppComponent } from './app.component';

​

@NgModule({

  declarations: [AppComponent],

  imports: [BrowserModule, FormsModule],

  providers: [],

  bootstrap: [AppComponent],

})

export class AppModule {}

​

// app.component.ts

import { Component } from '@angular/core';

​

@Component({

  selector: 'app-root',

  template: `

    <div>

      <label for="name">Name:</label>

      <input id="name" [(ngModel)]="name" />

      <p>Hello, {{ name }}!</p>

    </div>

  `,

})

export class AppComponent {

  name: string = '';

}

​

const express = require('express');

const app = express();

​

app.use(express.json());

​

// Example route

app.get('/', (req, res) => {

  throw new Error('Something went wrong!');

});

​

// Error-handling middleware

app.use((err, req, res, next) => {

  console.error(err.stack);

  res.status(500).json({ error: err.message });

});

​

app.listen(3000, () => {

  console.log('Server is running on port 3000');

});

​

@Value("${some.key:my default value}")

private String stringWithDefaultValue;

​