Is it possible to make/ change the function of a cord?

I want to know if it is possible to change the end of a cord. For example, let's say you have an HDMI cord and an Apple (iPhone etc) cord. Is it possible to maybe cut the two apart and wire the apple cord to the Apple cord so that the cord is HDMI to Apple? If there's any way to sort of "fuse" two cords together, please let me know.

Umm first of all you need to know what parts of the apple cord are going to what parts and softwares of the iphone or what ever and then you need to connect them to the correct parts of the hdmi cord and then plus third i don't even know if you know how to solder " aka for you Fuse" i sugest just buy a iphone to hdmi cord

You understand nothing.

HDMI signals can't be directly connected to anything
other than HDMI (or, with a plug adapter, DVI) jacks.

This is because the signals carried by these connections
are unique -- nothing else can handle them.

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It is sometimes possible to get by with only basic knowledge,
but if you want to join dissimilar cables or make your own,
it becomes necessary to "know all there's to know"
about the type of signal involved, the pinout of each connector,
the type(s) of wire or cable that are and are not suited to the task,
and other important information.

Almost anyone can learn what they need to know,
but it requires some effort and may take a long time.