jQuery if statement, syntax

jQuery is just a library which enhances the capabilities of the DOM within a web browser; the underlying language is JavaScript, which has, as you might hope to expect from a programming language, the ability to perform conditional logic, i.e.

if( condition ) {
    // do something
}

Testing two conditions is straightforward, too:

if( A && B ) {
    // do something
}

Dear God, I hope this isn't a troll...

You can wrap jQuery calls inside normal JavaScript code. So, for example:

$(document).ready(function() {
    if (someCondition && someOtherCondition) {
        // Make some jQuery call.
    }
});