Here, we have created an object <code>obj</code> which will be an instance of <code>Object</code> and similarly function <code>fun</code> will be an instance of <code>Function</code>. Now lets breakdown each comparison:
<ol>
<li><code>obj.toString</code> method is inherited from Object.prototype while <code>Object.toString</code> refers to the toString method directly on the Object constructor function itself. These both point to two different functions and hence log false</li>
<li>Since all functions in JavaScript inherit from Function.prototype, <code>fun.toString</code> is equivalent to the same method defined on Function.prototype. Thus, it logs true</li>
<li>Every object in JavaScript inherits properties and methods from its prototype. Since the prototype of any object is Object.prototype, <code>obj.toString</code> is equivalent to <code>Object.prototype.toString</code>. Logs true</li>
<li>Similar to <code>2.</code> , all functions in JavaScript inherit from Function.prototype. Logs true</li>
<li><code>Object.toString</code> is directly available on the Object constructor function itself while <code>Object.prototype.toString</code> method resides on the prototype of Object making each of them distinct entities. Logs false</li>
<li><code>Function.toString</code> looks for the toString method on the <code>Function</code> object itself. If its not found there, it'll look up the prototype chain and find it on <code>Function.prototype</code>. Therefore, both expressions essentially point to the same method. Logs true</li>
</ol>
<pre class="shiki github-dark shaku"><code>const obj = {}const fun = () =&gt; {}console.log(obj.toString === Object.toString) // falseconsole.log(fun.toString === Function.toString) // trueconsole.log(obj.toString === Object.prototype.toString) // trueconsole.log(fun.toString === Function.prototype.toString) // trueconsole.log(Object.toString === Object.prototype.toString) // falseconsole.log(Function.toString === Function.prototype.toString) // true</code></pre>

instance vs class vs prototype methods

What does the code snippet to the right output by console.log?…