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I am trying to carry out multiple checks on some input data. I am doing this
by the running the data through a number of functions. i.e. I have an
onclick that calls a function, which in turn calls the test functions.

My problem is getting the testing to stop if one of the tests fails and
await for the input to be amended.
I believe that this is because the when the testing function has finished it
returns the script to the point immediately AFTER the function was called,
i.e. it simply carries on to the next test and hence to completetion of the
script.

How do I overcome this problem?

Many thanks
Phil

> I am trying to carry out multiple checks on some input data. I am doing this
> by the running the data through a number of functions. i.e. I have an
> onclick that calls a function, which in turn calls the test functions.
>
> My problem is getting the testing to stop if one of the tests fails and
> await for the input to be amended.
> I believe that this is because the when the testing function has finished it
> returns the script to the point immediately AFTER the function was called,
> i.e. it simply carries on to the next test and hence to completetion of the
> script.
>
> How do I overcome this problem?

Have each function return true if the input is ok. Then use if statements.
if (test1()) {
if (test2()) {
if (test3()) {
...

http://www.crockford.com/#javascript

Have each function return a boolean indicating it's success. Sorry js isn't
my forte I'm just lurnking while I wait for an answer to one of my posts ,
so syntax could be way off. But general idea is this:

function checkTheInput()
{
if (firstCheck())
{
if (secondCheck())
{
if (thirdCheck())
{
alert('all 3 cheks were ok');
}
else
{
alert('thirdCheck() failed');
}
}
else
{
alert('secondCheck() failed');
}
{
else
{
alert('firstCheck() failed');
}
}

function firstCheck()
{
//if data is ok return true, otherwise return false
}

function secondCheck()
{
//ditto
}

etc...

"Philip WATTS" <> wrote in message
news:bnug4o$ts6$...
> I am trying to carry out multiple checks on some input data. I am doing
this
> by the running the data through a number of functions. i.e. I have an
> onclick that calls a function, which in turn calls the test functions.
>
> My problem is getting the testing to stop if one of the tests fails and
> await for the input to be amended.
> I believe that this is because the when the testing function has finished
it
> returns the script to the point immediately AFTER the function was called,
> i.e. it simply carries on to the next test and hence to completetion of
the
> script.
>
> How do I overcome this problem?
>
> Many thanks
> Phil
>
>

Philip WATTS wrote:

> My problem is getting the testing to stop if one of the tests fails and
> await for the input to be amended.
> I believe that this is because the when the testing function has finished it
> returns the script to the point immediately AFTER the function was called,
> i.e. it simply carries on to the next test and hence to completetion of the
> script.
>
> How do I overcome this problem?

Instead of using nested if-statements you could simply `return false'
if a check fails. I find this more practical since you can add tests
without further nested block statements (and without indentation which
should have been done then for the sake of legibility):

function testMe()
{
if (!test1())
return false;
if (!test2())
return false;
if (!test3())
return false;

return true; // passed all tests
}


PointedEars

Thomas 'PointedEars' Lahn <> writes:

> function testMe()
> {
> if (!test1())
> return false;
> if (!test2())
> return false;
> if (!test3())
> return false;
>
> return true; // passed all tests
> }

That sounds like a job for short-circuit boolean operators!

function testMe() {
return test1() && test2() && test3();
}

/L
--
Lasse Reichstein Nielsen -
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleDOM.html>
'Faith without judgement merely degrades the spirit divine.'

Lasse Reichstein Nielsen wrote:

> Thomas 'PointedEars' Lahn <> writes:
>> function testMe()
>> {
>> if (!test1())
>> return false;
>> if (!test2())
>> return false;
>> if (!test3())
>> return false;
>>
>> return true; // passed all tests
>> }
>
> That sounds like a job for short-circuit boolean operators!
>
> function testMe() {
> return test1() && test2() && test3();
> }

Not if you, like the OP, want to know *which*
test failed (which I omitted in the above code):

function ...(...)
{
if (!test1())
alert("Test 1 failed!");
return false;
}
...
return true; // passed all tests
}


PointedEars

Thomas 'PointedEars' Lahn wrote on 01 nov 2003 in comp.lang.javascript:

> Not if you, like the OP, want to know *which*
> test failed (which I omitted in the above code):
>
> function ...(...)
> {
> if (!test1())
> alert("Test 1 failed!");
> return false;
> }
> ...
> return true; // passed all tests
> }

Thet you should put an extra { where it belongs:

function testing() {
if !test1() {
alert("Test 1 failed!");
return false;
}
...
alert("passed all tests");
return true;
}



--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

Thomas 'PointedEars' Lahn wrote:

> Philip WATTS wrote:
>
> > My problem is getting the testing to stop if one of the tests fails and
> > await for the input to be amended.
> > I believe that this is because the when the testing function has finished it
> > returns the script to the point immediately AFTER the function was called,
> > i.e. it simply carries on to the next test and hence to completetion of the
> > script.
> >
> > How do I overcome this problem?
>
> Instead of using nested if-statements you could simply `return false'
> if a check fails. I find this more practical since you can add tests
> without further nested block statements (and without indentation which
> should have been done then for the sake of legibility):
>
> function testMe()
> {
> if (!test1())
> return false;
> if (!test2())
> return false;
> if (!test3())
> return false;
>
> return true; // passed all tests
> }
>
> PointedEars

This is known as a "gauntlet" <url: http://mindprod.com/jgloss/gauntlet.html />,
specfically an "Early Return Style Gauntlet".

I used to detest this type of code, it seemed sloppy and ugly, however, as I write
more and more code, I find myself using the style more and more often, because as
Roedy points out "I like this style because the conditions are independent and
uniform. You can shuffle the order easily and add new conditions without having
the adjust the existing code.".

--
| Grant Wagner <>

* Client-side Javascript and Netscape 4 DOM Reference available at:
*
http://devedge.netscape.com/library/...ce/frames.html

* Internet Explorer DOM Reference available at:
*
http://msdn.microsoft.com/workshop/a...ence_entry.asp

* Netscape 6/7 DOM Reference available at:
* http://www.mozilla.org/docs/dom/domref/
* Tips for upgrading JavaScript for Netscape 7 / Mozilla
* http://www.mozilla.org/docs/web-deve...upgrade_2.html

Evertjan. wrote:

> Thomas 'PointedEars' Lahn wrote [...]:
>> Not if you, like the OP, want to know *which*
>> test failed (which I omitted in the above code):
>>
>> function ...(...)
>> {
>> if (!test1())
>> alert("Test 1 failed!");
>> return false;
>> }
>> ...
>> return true; // passed all tests
>> }
>
> Thet you should put an extra { where it belongs:
>
> function testing() {
> if !test1() {

Also nitpicking, the `if' statement requires
parantheses around the conditional expression.


PointedEars

Thomas 'PointedEars' Lahn wrote on 23 nov 2003 in comp.lang.javascript:

>> Thet you should put an extra { where it belongs:
>>
>> function testing() {
>> if !test1() {
>
> Also nitpicking, the `if' statement requires
> parantheses around the conditional expression.

Pick nit and be my guest

"requires" by definition or by erroring out ?

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)