Exit from a Client Side function in Lightning?

Question

Trying to do a if statement in a client side function. If the statement is true, you proceed with the action. If not, you exit from the function. Is this possible?

doInit : function(component, event, helper) {
    if (this is true) {
        var action = component.get("c.getPickListValuesFromSubjects");
        action.setCallback(this, function(response) {            
            var state = response.getState();
            if (state === "SUCCESS") {
                var pickListValues = response.getReturnValue();
                component.set("v.optionsForSubject", pickListValues);
            } 
            else {
                console.log(state);
            }
        });     
        $A.enqueueAction(action);}
    exit;
},

Answer 1

You need to leverage the return statement in your javascript.

doInit: function(component, event, helper) {
    if (!(this is true)) { // if the value is not true
        return;            // return control back to the caller
    }                      // do not proceed any further

    var action = component.get("c.getPickListValuesFromSubjects");
    action.setCallback(this, function(response) {
        var state = response.getState();
        if (state === "SUCCESS") {
            var pickListValues = response.getReturnValue();
            component.set("v.optionsForSubject", pickListValues);
        } else {
            console.log(state);
        }
    });
    $A.enqueueAction(action);
}