CSS

Y-Scroll just to a component

You need to set a fixed height

.component {
  height: 100vh;
  overflow-y: scroll;
}

Use "..." when the text exceed component width

.component {
  text-overflow: ellipsis;
}

JS

Ternary If/Else

a = 1
b = 2
 
c = a == 1 ? a : b

without "else"

a = 1
b = 2
 
c = a == 1 && a

just the "else"

a = 1
b = 2
 
c = a != 1 || b

referencies

Rocketseat: https://rocketseat.com.br/