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JavaScript Object-Oriented JavaScript: Challenge Making the Game Interactive Build the moveLeft() and moveRight() Methods

Posted by Ewerton Luna
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Ewerton Luna
Full Stack JavaScript Techdegree Graduate 24,031 Points

Inside moveLeft() and moveRight(), instead of updating htmlToken.style.left, why don't we update htmlToken.offsetLeft?

Before seeing the solution, I thought these methods would be done using the Node Element property 'offsetLeft' instead of using the CSS property 'left'.

Would it be correct to use this other way? If so, there's a reason to why she didn't use it?

Thank you!

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

The instruction does use the "offsetLeft" property to get the current position. But to change the position, the "left" CSS style property is used.

This is because "offsetLeft" is a read-only property and cannot be changed directly. For more details, see the MDN page on HTMLElement.offsetLeft .

Ewerton Luna
.a{fill-rule:evenodd;}techdegree seal-36
Ewerton Luna
Full Stack JavaScript Techdegree Graduate 24,031 Points

Thanks, Steven! I did read that offsetLeft is a read-only property, but I didn't connect the dots :/ Thank you very much for taking the time and clearing that up!