Assign only if condition is true in ternary operator in JavaScript

Question

Is it possible to do something like this in JavaScript?

max = (max < b) ? b; 

In other words, assign value only if the condition is true. If the condition is false, do nothing (no assignment). Is this possible?

Answer 1

Don't use the ternary operator then, it requires a third argument. You would need to reassign max to max if you don't want it to change (max = (max < b) ? b : max).

An if-statement is much more clear:

if (max < b) max = b; 

And if you need it to be an expression, you can (ab)use the short-circuit-evaluation of AND:

(max < b) && (max = b) 

Btw, if you want to avoid repeating variable names (or expressions?), you could use the maximum function:

max = Math.max(max, b); 

Answer 2

An expression with ternary operator must have both values, i.e. for both the true and false cases.

You can however

max = (max < b) ? b : max; 

in this case, if condition is false, value of max will not change.