两次返回似乎不起作用

Question

I have html running javascript after form,

form name="mortgage" method="post" action=" "onsubmit="return completeFormValidation();">

And javascript code for validation,

mainFunction:

function completeFormValidation() {

return yearentry1();

return my_location();


} // End of completeFormValidation

1st function in main:

function yearentry1(){

     var yearval = document.mortgage.mortYear.value;
     alert(yearval);

}

2nd function in main:

function my_location(){

  var numradio = document.mortgage.propLocation.length;
  var selected="";

  for(var i=0; i < numradio; i++){

    if(document.mortgage.propLocation[i].checked == true){
        selected += "Selected radio item " + i;

    }
  }

  if(selected == ""){

    document.getElementById("reserved").innerHTML = "<p> none radio selected </P>";
    return false;

  }

}

returning two times doesn't seem to work! when 1st function passes and returns TRUE the function quits and sends the form.

is it possible if i can have all functions run in the main function and then return false if any of the functions inside main returned false?

Answer 1

The "return" statement ends the function, so you can't call anything after this.

Wrong:

function completeFormValidation() {
    return my_yearentry();
    return my_location();
}

Correct:

function completeFormValidation() {
    return my_yearentry() && my_location();
}

But your my_yearentry function must have a boolean return value.

Answer 2

This won't work, because neither of your other functions are ready, but ideally you would want to do something like:

function completeFormValidation() {
    return my_yearentry() && my_location();
}

The trouble is neither of the other functions always return something useful either.

If they both always returned (and ideally returned true or false ) then this would work.

Perhaps

function yearentry1(){
    var yearval = document.mortgage.mortYear.value;
    return yearval;
}

and

function my_location(){
    if(selected == ""){
        document.getElementById("reserved").innerHTML = "<p> none radio selected </P>";
        return false;
    }
    return true;
}

although mixing together your validation checks and your validation reporting might also be problematic. This could be a good start.

Answer 3

Once a function returns, that function call is finished.

function completeFormValidation() {

    my_yearentry(); // take away return statement, just call the function
                    // you have inconsistent function name below :"yearentry1()"

    return my_location();
}

Answer 4

Presumably, you would like to only submit the form if both functions return false. In that case, you would want the following:

function completeFormValidation() {

    return my_yearentry() && my_location();    
}

http://jsfiddle.net/LgepA/1/

&& is "and".

In this case if the first function returns false, the 2nd won't even be executed. If you want 2nd to always execute, you can use simply & :

function completeFormValidation(){

    return !!(my_yearentry() & my_location());   
}

http://jsfiddle.net/LgepA/3/

Or in a more readable manner:

function completeFormValidation(){

    var yearResult = my_yearentry();
    var locationResult = my_location();

    return yearResult && locationResult;   
}

http://jsfiddle.net/LgepA/4/