How do you use the ? : (conditional) operator in JavaScript?

Question

In simple words, what is the ?: (conditional, "ternary") operator and how can I use it?

Answer 1

Ternary expressions are very useful in JS, especially React. Here's a simplified answer to the many good, detailed ones provided.

condition ? expressionIfTrue : expressionIfFalse

Think of expressionIfTrue as the OG if statement rendering true;
think of expressionIfFalse as the else statement.

Example:

var x = 1;
(x == 1) ? y=x : y=z;

this checked the value of x, the first y=(value) returned if true, the second return after the colon : returned y=(value) if false.