using 4021 parallel shift register with internal pullup resistor

I need 8 buttons and thought of using a 4021 IC.
On every tutorial there's a pull up or down resistor for every button. would it be possible to just connect the buttons from 4021 to GND and instead use the arduino internal pullup on the DATA PIN?


Do you understand the function of a pull up or down resistor has ?
If so you should be able to figure out the answer.
Remember that this MPX isn't an array of relays you are switching.

haha, thanks for the answers!

The pullup resistor is so the input is at all times connected to one level or another and doesn't gets floating between values, right? I thought it could work as the bits that the register sends don't get floating also, but I guess it's not the same principle.


That's what an analog switch (relay) would do,
The MPX isn't bi-directional, and therefore doesn't do what you imagined.

Read the first page of the datasheet about "shifting" and "jamming" bits.