Visualforce page doesn’t support ternary operator. But, Apex support.

Visualforce page supports IF function. We can achieve the same using this.

Syntax:

IF ( logical_test, value_if_true, value_if_false )

Example:

{! IF( Account.Size__c == null, ’10’, Account.Size__c ) }

In the above example, if the Account’s Size is null, it will default to 10. Else, it will display the Account’s size.