How To Use Object Methods in JavaScript

<span class="hljs-comment">// Initialize an object with properties and methods</span>
<span class="hljs-keyword">const</span> job = {
    position: <span class="hljs-string">'cashier'</span>,
    type: <span class="hljs-string">'hourly'</span>,
    isAvailable: <span class="hljs-literal">true</span>,
    showDetails() {
        <span class="hljs-keyword">const</span> accepting = <span class="hljs-keyword">this</span>.isAvailable ? <span class="hljs-string">'is accepting applications'</span> : <span class="hljs-string">"is not currently accepting applications"</span>;

        console.log(`The ${<span class="hljs-keyword">this</span>.position} position is ${<span class="hljs-keyword">this</span>.type} and ${accepting}.`);
    }
};

<span class="hljs-comment">// Use Object.create to pass properties</span>
<span class="hljs-keyword">const</span> barista = <span class="hljs-built_in">Object</span>.create(job);

barista.position = <span class="hljs-string">"barista"</span>;
barista.showDetails();

Object.keys()

Object.keys() creates an array containing the keys of an object.

We can create an object and print the array of keys.

<span class="hljs-comment">// Initialize an object</span>
<span class="hljs-keyword">const</span> employees = {
    boss: <span class="hljs-string">'Michael'</span>,
    secretary: <span class="hljs-string">'Pam'</span>,
    sales: <span class="hljs-string">'Jim'</span>,
    accountant: <span class="hljs-string">'Oscar'</span>
};

<span class="hljs-comment">// Get the keys of the object</span>
<span class="hljs-keyword">const</span> keys = <span class="hljs-built_in">Object</span>.keys(employees);

console.log(keys);


Output

["boss", "secretary", "sales", "accountant"]

Object.keys can be used to iterate through the keys and values of an object.

<span class="hljs-comment">// Iterate through the keys</span>
<span class="hljs-built_in">Object</span>.keys(employees).forEach(key => {
    <span class="hljs-keyword">let</span> value = employees[key];

     console.log(`${key}: ${value}`);
});

Output

boss: Michael
secretary: Pam
sales: Jim
accountant: Oscar