garethhall Posted May 28, 2009 Share Posted May 28, 2009 Hello Guys, Can some please me and tel how can I pass a null or no value to a function. I have the 2 scripts below and I am writing my JS this way so I can recall it and use it on multiple pages. But as I am sure you can see I don't have a form element called lastName and Fax thus my JS return an undefined error. So When I call me function how do I tell it that that element does not exists? I always thought I can just leave in blank or pass it nothing like this " " but I am wrong? HTML Page <form name="frmContact" method="post"> <table cellpadding="0" cellspacing="0" border="0" width="100%"> <tr> <td align="right" width="15%" class="label">Name:</td> <td width="85%" ><input type="text" name="name" class="textfield"/></td> <td > </td> <td><span id="spn_name"></span></td> </tr> <tr> <td align="right" class="label">Phone:</td> <td ><input type="text" name="phone" class="textfield"/></td> <td > </td> <td><span id="spn_phone"></span></td> </tr> <tr> <td align="right" class="label">Email:</td> <td ><input type="text" name="email" class="textfield"/></td> <td > </td> <td><span id="spn_email"></span></td> </tr> <tr> <td align="right" valign="top" class="label">Message:</td> <td ><textarea name="message" cols="20" rows="5" class="textarea"></textarea></td> <td > </td> <td></td> </tr> <tr> <td align="right" valign="top" class="label"> </td> <td ><input type="button" name="submit" id="submit" value="Submit" onclick="validate('frmContact', 'name', '', 'email', 'phone', '', 'CMS/cmsImages/approvedMark.gif', 'CMS/cmsImages/rejectMark.png');"/></td> <td > </td> </tr> </table> </form> Javascript // Validation Filters var emailReg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/; var nameReg = /[A-Za-z\'\-]/; var phoneReg = /[0-9\(\)\-\+ ]{7,16}/; function validate(frmName, fieldName, fieldLastName, fieldEmail, fieldPhone, fieldFax, apprvMK, rejectMK){ // Set Variables to hold values and followed by Element Name var name = document.forms[frmName].elements[fieldName].value; var nameElementName = document.forms[frmName].elements[fieldName].name; var lastName = document.forms[frmName].elements[fieldLastName].value; var lastNameElementName = document.forms[frmName].elements[fieldLastName].name; var emailAddress = document.forms[frmName].elements[fieldEmail].value; var emailElementName = document.forms[frmName].elements[fieldEmail].name var phone = document.forms[frmName].elements[fieldPhone].value; var phoneElementName = document.forms[frmName].elements[fieldPhone].name; var fax = document.forms[frmName].elements[fieldFax].value; var faxElementName = document.forms[frmName].elements[fieldFax].name; // This runs the validation and updates the Page function runValidation(myField, MyReg, MyElementName){ if(!myField.match(MyReg)){ document.getElementById("spn_"+MyElementName).innerHTML = "<img src='"+rejectMK+"' width='12' height='12' />"; }else{ document.getElementById("spn_"+MyElementName).innerHTML = "<img src='"+apprvMK+"' width='12' height='12' />"; } } runValidation(name, nameReg, nameElementName); runValidation(lastName, nameReg, lastNameElementName); runValidation(emailAddress, emailReg, emailElementName); runValidation(phone, phoneReg, phoneElementName); runValidation(fax, phoneReg, faxElementName); } Quote Link to comment https://forums.phpfreaks.com/topic/159966-solved-how-to-pass-nothing-to-a-function/ Share on other sites More sharing options...
Ken2k7 Posted May 28, 2009 Share Posted May 28, 2009 Just remove it from the validation altogether. HTML <form name="frmContact" method="post"> <table cellpadding="0" cellspacing="0" border="0" width="100%"> <tr> <td align="right" width="15%" class="label">Name:</td> <td width="85%" ><input type="text" name="name" class="textfield"/></td> <td > </td> <td><span id="spn_name"></span></td> </tr> <tr> <td align="right" class="label">Phone:</td> <td ><input type="text" name="phone" class="textfield"/></td> <td > </td> <td><span id="spn_phone"></span></td> </tr> <tr> <td align="right" class="label">Email:</td> <td ><input type="text" name="email" class="textfield"/></td> <td > </td> <td><span id="spn_email"></span></td> </tr> <tr> <td align="right" valign="top" class="label">Message:</td> <td ><textarea name="message" cols="20" rows="5" class="textarea"></textarea></td> <td > </td> <td></td> </tr> <tr> <td align="right" valign="top" class="label"> </td> <td ><input type="button" name="submit" id="submit" value="Submit" onclick="validate('frmContact', 'name', 'email', 'phone', 'CMS/cmsImages/approvedMark.gif', 'CMS/cmsImages/rejectMark.png');"/></td> <td > </td> </tr> </table> </form> JavaScript // This runs the validation and updates the Page function runValidation(myField, MyReg, MyElementName){ if(!myField.match(MyReg)){ document.getElementById("spn_"+MyElementName).innerHTML = "<img src='"+rejectMK+"' width='12' height='12' />"; }else{ document.getElementById("spn_"+MyElementName).innerHTML = "<img src='"+apprvMK+"' width='12' height='12' />"; } } // Validation Filters var emailReg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/; var nameReg = /[A-Za-z\'\-]/; var phoneReg = /[0-9\(\)\-\+ ]{7,16}/; function validate(frmName, fieldName, fieldEmail, fieldPhone, apprvMK, rejectMK){ // Set Variables to hold values and followed by Element Name var name = document.forms[frmName].elements[fieldName].value; var nameElementName = document.forms[frmName].elements[fieldName].name; var emailAddress = document.forms[frmName].elements[fieldEmail].value; var emailElementName = document.forms[frmName].elements[fieldEmail].name var phone = document.forms[frmName].elements[fieldPhone].value; var phoneElementName = document.forms[frmName].elements[fieldPhone].name; runValidation(name, nameReg, nameElementName); runValidation(emailAddress, emailReg, emailElementName); runValidation(phone, phoneReg, phoneElementName); } Quote Link to comment https://forums.phpfreaks.com/topic/159966-solved-how-to-pass-nothing-to-a-function/#findComment-843872 Share on other sites More sharing options...
garethhall Posted May 28, 2009 Author Share Posted May 28, 2009 I know but that is the easy way out I am wanting my code to be as reusable as it can be. If I take it out and say I have another page that does need to validate those 2 fields then I would have to make a separate function or script. Quote Link to comment https://forums.phpfreaks.com/topic/159966-solved-how-to-pass-nothing-to-a-function/#findComment-844464 Share on other sites More sharing options...
Ken2k7 Posted May 28, 2009 Share Posted May 28, 2009 // Validation Filters var emailReg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/; var nameReg = /[A-Za-z\'\-]/; var phoneReg = /[0-9\(\)\-\+ ]{7,16}/; function validate(frmName, fieldName, fieldLastName, fieldEmail, fieldPhone, fieldFax, apprvMK, rejectMK){ // Set Variables to hold values and followed by Element Name var name = document.forms[frmName].elements[fieldName].value; var nameElementName = document.forms[frmName].elements[fieldName].name; var lastName = document.forms[frmName].elements[fieldLastName].value; var lastNameElementName = document.forms[frmName].elements[fieldLastName].name; var emailAddress = document.forms[frmName].elements[fieldEmail].value; var emailElementName = document.forms[frmName].elements[fieldEmail].name var phone = document.forms[frmName].elements[fieldPhone].value; var phoneElementName = document.forms[frmName].elements[fieldPhone].name; var fax = document.forms[frmName].elements[fieldFax].value; var faxElementName = document.forms[frmName].elements[fieldFax].name; // This runs the validation and updates the Page function runValidation(myField, MyReg, MyElementName){ if(!myField.match(MyReg)){ document.getElementById("spn_"+MyElementName).innerHTML = "<img src='"+rejectMK+"' width='12' height='12' />"; }else{ document.getElementById("spn_"+MyElementName).innerHTML = "<img src='"+apprvMK+"' width='12' height='12' />"; } } runValidation(name, nameReg, nameElementName); if (lastName !== '') runValidation(lastName, nameReg, lastNameElementName); runValidation(emailAddress, emailReg, emailElementName); runValidation(phone, phoneReg, phoneElementName); if (fax !== '') runValidation(fax, phoneReg, faxElementName); } Quote Link to comment https://forums.phpfreaks.com/topic/159966-solved-how-to-pass-nothing-to-a-function/#findComment-844485 Share on other sites More sharing options...
.josh Posted May 30, 2009 Share Posted May 30, 2009 <script language="javascript"> function blah(a,b,c) { if (a == null) alert('a is null'); } </script> <a href='' onclick="blah(1,2,3);">a is not null</a><br/> <a href='' onclick="blah(null,2,3);">a is null</a><br/> Quote Link to comment https://forums.phpfreaks.com/topic/159966-solved-how-to-pass-nothing-to-a-function/#findComment-845443 Share on other sites More sharing options...
bibby Posted June 1, 2009 Share Posted June 1, 2009 '', undefined, null, 0, NaN are all in the "nothing family" , in that they fail to pass if if(x){} They sometimes == each other, but not never === , such as undefined == null '' == false 0 == '' NaN is neither true, false, or null, but is still a number Quote Link to comment https://forums.phpfreaks.com/topic/159966-solved-how-to-pass-nothing-to-a-function/#findComment-847344 Share on other sites More sharing options...
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