How do you memorize chords and scales?

You just have to do it with a tremendous amount of repeating. Start with major C chord in all positions - add the 6th and 7th and get used to the sound. Do the C scale two or three octaves with both hands. Take it slow and study the fingering - and pound that memory into your brain.

You got to figure that a lot of people started when they were 4 or 5 years old - and these people will know this stuff like they always knew it..... it's second nature. So that's what you need to do.

yes , and basic musical knowledge.
piano is actually a lot easier for chords than guitar.
a major chord is 1-3-5
A minor chord is 1 -flatted 3 and 5
for a 7th just add the 7 to the 1-3-5
etc....
For soloing and stuff it is just talent, musical knowledge and knowing what is flatted or sharped in a scale
Guitar is easy for scales, because a basic scale pattern can be started in 13 places,
all you need to know is the finger pattern.
But it takes YEARS to perfect and be comfortable with.
Basic signposts exist in the dotted frets
Just like the black keys on a piano.
practice practive practice, patience and musical lust is needed.
you wanna play to be cool or fit in? don't waste your time or anyone elses...

wayne came closest. There's a typo in his answer; it should be F Ab C Eb.

If you learn music theory you don't have to memorize anything because you understand how to construct any chord or scale. Counting half-steps is just one way to do it.

That said, you will memorize all your key signatures after learning the formulas because you'll want that info at instant recall in real time. But knowing the theory will make learning those patterns way easier to do, because you'll have a lot of different ways to think about any given chord or scale.

I created a way to note read music with shapes and colors on violin that may be an alternative way to learn scales if you are good at memorizing color sequence patterns for notes rather than the note names themselves. Check it out if you like. Just google "note read with shapes and colors on violin adria sorensen

keep on practicing them and try to recite them out