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Once again, we need to be careful of the reference trap.

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There are two ways to fall for this trap, it can happen by mishandling arrays and objects.

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In this lesson, we're going to see how this trap occurs when mishandling objects.

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A trap happens when many variables a reference to one object.

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If I update the object through one variable, it's going to affect the other.

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To avoid the trap, do not set class variables equal to each other.

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Sound familiar?

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I hope so.

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I told you the same thing about array variables.

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The see this inaction will add another variable in Nissan to.

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And we'll set it equal to the Nissan object.

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And for now, I'd like to remove the setas.

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Then we're going to print the fields from Nissan to.

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OK, nothing weird so far.

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Now, what if I decide to paint the second Nissan yellow?

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Run the code.

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Oh, I meant the only update, the second Nisan, but now the first Nissan is yellow as well.

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You fell into the trap.

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When you set a variable equal to another, it copies the value inside.

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In this case, what's inside is a reference and now both variables share a reference that points to

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the same object.

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If I update the object, the one variable, it's going to affect the other.

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This is bad.

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The state of a variable should not change because you updated another, the reference shop can make

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your code dangerous and unpredictable.

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The solution is to make a new object, don't be lazy is create a new object.

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Inside your code set the variable Nissan to equal to a new object.

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And after creating a new object called the constructor, by passing the four values that it needs to

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update your fields.

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All right, run your code.

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And as I expect, all of the objects are independent of each other.

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Instead of setting the variables equal to each other, we made a new object and now my mind is at peace.

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I can take comfort knowing that each variable points to a unique object.

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I don't have to worry about the state of one variable being affected by another.

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This is a great solution, so we can update our table of traps.

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Don't worry, it's all in your cheat sheet.

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So far, we went over to reference drops in this video, we talked about the second trap do not set

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object variables equal to each other.

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This doesn't copy the object.

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It copies the reference.

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Instead, set your variable equal to a new object.

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It's much better if a variable points to a unique object, then you don't have to worry about the state

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of one variable being affected by another.