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JavaScript Quiz – can isFrozen method really check freeze object

JavaScript Quiz – can isFrozen method really check freeze object

Object isFrozen Method –

Object isFrozen Method (Object.isFrozen()) is a method that checks whether the object is freeze or not. As there is Object.frozen() method is also there which can restrict the change of the value of the object key.

Object.isFrozen() method return a boolean value which means if an object is frozen then it returns true otherwise it returns false

It’s syntax looks like –


For more detail about the javascript object isFrozen method click here.

JavaScript Question

In this javascript quiz code, you need to find out can isFrozen method really checks the frozen javascript object and what it returns.

First, we declare a variable object using let keyword and assign an javascript object to it. Which contain only one key-value pair.

let object = { name : “JS Startup” }

Now, create an another variable isFrozen and assign the value return from Object.isFrozen() method in which we pass object variable as parameter.

let isFrozen = Object.isFrozen(object);

Finally, we are checking the value of isFrozen variable using the console log And guess what should be the output will print.

Answer – false

Click To Run Code


Now, you know the answer is false. but why it can be true. Let me explain it.

As we are checking the object variable is frozen or not. But when we assign javascript object to object variable it is in non-frozen mode.

In order to freeze an object, you need to pass javascript object to Object.freeze() method.

So, there is no Object.freeze() method is used.

At last, That’s why we get an answer “false“.

I hope you understand the concept and logic behind it.

But wait, i have something more for you –

Check out our other javascript quiz – 

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  2. JS Quiz – Reverse array element but in the same position
  3. JavaScript Quiz – filter array method based on the element size
  4. JS Quiz – copy object with JSON stringify and parse method


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