If the password is the same as the db_password If username is the same as the db_username and Otherwise, they will be given the option to try try again or reset their password, if they have forgotten it.īased on this, we can imagine that the logic of our code would like something like this: If a user provides the correct credentials, they’re allowed into the member area. A user needs to provide login credentials before gaining access to the member part of the application. Based on the results, Javascript will execute sections of code.Īs an example, let’s consider an application with a dedicated area for its members. Javascript allows us to control the flow of our program through expressions that evaluate certain conditions.

How to nest if, else if and else statements.

Multiple conditions inside a single if statement.

What are conditional control statements.

We also cover how to evaluate multiple conditions inside a single conditional statement, and how to nest conditionals inside each other. We cover the if statement, the else if ladder and the else catch all fallback, as well as the shorthand ternary operator ( ? : ).

In this Javascript tutorial we learn how to use if, else if and else statements to control the flow of our applications conditionally. It's the only one JavaScript currently has, though.If, else if, else Javascript if, else if, else (conditional control) Tutorial They can even be chained: serveDrink(userIsYoungerThan4 ? 'Milk' : userIsYoungerThan21 ? 'Grape Juice' : 'Wine') īe careful, though, or you will end up with convoluted code like this: var k = a ? (b ? (c ? d : e) : (d ? e : f)) : f ? (g ? h : i) : j ġ Often called 'the ternary operator,' but in fact it's just a ternary operator. Like all expressions, the conditional operator can also be used as a standalone statement with side-effects, though this is unusual outside of minification: userIsYoungerThan21 ? serveGrapeJuice() : serveWine() ServeDrink(userIsYoungerThan21 ? 'Grape Juice' : 'Wine')

This can be shortened with the ?: like so: var userType = userIsYoungerThan18 ? 'Minor' : 'Adult' Here is an example of code that could be shortened with the conditional operator: var userType

This is a one-line shorthand for an if-else statement.

Javascript conditional