Posts - Page 6 - Philip Ackermann

Neues Node.js-Buch

July 2016

Map array values to function parameters

Problem

You want to map values of an array to function parameters in ES5.

Ingredients

1 function
1 array
the apply() method

Directions

Given: a function that takes different parameters and an array containing concrete arguments.
```
function add(x, y, z) {
  return x + y + z;
}
var parameters = [2, 3, 4];
```

June 2016

Define static properties using the class syntax

Problem

You want to define a static property inside a “class”.

Ingredients

1 “class”
1 property

Directions

Create a “class”.

class SomeClass {
  constructor(property) {
    this.property = property;
  }
}

June 2016

Define static methods using the class syntax

Problem

You want to define a static method inside a “class”.

Ingredients

1 “class”
1 method
the static keyword

Directions

Create a “class”.

class SomeClass {
  constructor(property) {
    this.property = property;
  }
}

June 2016

Apply ES2015 class inheritance

Problem

You want to apply inheritance using the class syntax introduced in ES2015.

Ingredients

2 or more “classes”
the extends keyword
the super keyword

Directions

Define a “class”. Optionally define some properties, getter and setters.

'use strict';
class Animal {
  constructor(color) {
   this._color = color;
  }
  get color() {
    return this._color;
  }
  set color(color) {
    this._color = color;
  }
}

June 2016

Create getters and setters in class syntax

Problem

You want to create getters and setters for a class in ES2015.

Ingredients

1 class
the get and set keywords

Directions

Create a class with some properties.

class Person {
  constructor(firstName, lastName) {
    this._firstName = firstName;
    this._lastName = lastName;
  }
}