www.webdeveloper.com
Results 1 to 8 of 8

Thread: default values in functions

  1. #1
    Join Date
    Sep 2004
    Posts
    3

    Question default values in functions

    Hello

    I would like to call a function with parameters, i.e. multiply('2','3','box1').
    In this example, the first argument would be multiplied with the second and written into the div with the id="box1".

    My question:
    How can I set a default value for the third argument? => so if I call multiply('2','3') then it should automatically set the output-variable to 'box1' if not other defined in the call.

    I'm sure that this is possible but I unfortunately can't find anything about default values neither in this forum nor with google...

    Thank you for the answers,
    saimen

  2. #2
    Join Date
    Jul 2004
    Location
    Canada, eh
    Posts
    784
    Code:
    <html>
    <head>
    <title>function default</title>
    <script type="text/javascript">
    function add(a, b, id) {
    
      /* Here I set default values */
      if(!a) a=0;
      if(!b) b=0;
      if(!this.id) id="di1";
      /* End of default values */
    
      if(document.getElementById(id).childNodes.length==0) document.getElementById(id).appendChild(document.createTextNode(""));
      document.getElementById(id).firstChild.data=(a+b);
    }
    </script>
    </head>
    <body onload="add(1);">
    <div id="di1"></div>
    </body>
    </html>

  3. #3
    Join Date
    Sep 2004
    Posts
    3

    Post

    Hello
    Thank you for your answer. I've tried to apply it for my function. There is good news and bad news for me:
    good news: if targetDiv is not set, then it sets the value to "calendar". that's nice :o)
    bad news: if targetDiv is set, it overwrites the value with "calendar".
    => I've used the alerts to give out the values before and after the default settings...

    Maybe I'm making something wrong?!

    Code:
    function ShowCalendar(dateValue, sourceField, targetDiv) {
    	//alert("Funktion ShowCalendar, Variable dateValue: "+dateValue);
    
    	//set default variables for targetDiv
    	alert("Funktion ShowCalendar, Variable targetDiv: "+targetDiv);
    	if(!this.targetDiv) targetDiv="calendar";
    	alert("Funktion ShowCalendar, Variable targetDiv: "+targetDiv);

  4. #4
    Join Date
    Jul 2004
    Location
    Singapore, SG
    Posts
    654
    how are you calling this function? what are you passing to it?

  5. #5
    Join Date
    Sep 2004
    Posts
    3
    The function ShowCalendar(dateValue, sourceField, targetDiv) is called from a link in html:
    Code:
    	<a href="#" onclick="ShowCalendar(document.forms['formular1'].elements['startdatum'].value, 'startdatum'); return false;">
    	<img src="calendar.gif" alt="" border="0" />
    	</a>
    The values passed are (for example):
    dateValue: "2004-09-01" (or empty)
    sourceField: "startdatum" (never empty)
    targetDiv: "calendar2" (or empty)

  6. #6
    Join Date
    Jul 2004
    Location
    Singapore, SG
    Posts
    654
    remove the 'this.'

  7. #7
    Join Date
    Dec 2003
    Location
    Bucharest, ROMANIA
    Posts
    15,428
    Your function has 3 parameters, but you passed only 2 on event handler...

  8. #8
    Join Date
    Mar 2010
    Posts
    16
    You can't (well, at least shouldn't) use something like
    Code:
    if (!a)
    because false is a valid value (e.g. add(false)). What you need is Javascript's equivalence of
    PHP's isset
    .

    I wish Javascript would just support function foobar($value = "default value") like in PHP...

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
HTML5 Development Center

"

"

X vBulletin 4.2.2 Debug Information

  • Page Generation 0.18890 seconds
  • Memory Usage 2,916KB
  • Queries Executed 15 (?)
More Information
Template Usage (33):
  • (1)SHOWTHREAD
  • (1)ad_footer_end
  • (1)ad_footer_start
  • (1)ad_global_above_footer
  • (1)ad_global_below_navbar
  • (1)ad_global_header1
  • (1)ad_global_header2
  • (1)ad_navbar_below
  • (1)ad_showthread_firstpost_sig
  • (1)ad_showthread_firstpost_start
  • (1)ad_thread_first_post_content
  • (1)ad_thread_last_post_content
  • (4)bbcode_code
  • (1)footer
  • (1)forumjump
  • (1)forumrules
  • (1)gobutton
  • (1)header
  • (1)headinclude
  • (1)headinclude_bottom
  • (8)memberaction_dropdown
  • (1)navbar
  • (4)navbar_link
  • (1)navbar_moderation
  • (1)navbar_noticebit
  • (1)navbar_tabs
  • (2)option
  • (8)postbit
  • (8)postbit_onlinestatus
  • (8)postbit_wrapper
  • (1)spacer_close
  • (1)spacer_open
  • (1)tagbit_wrapper 

Phrase Groups Available (6):
  • global
  • inlinemod
  • postbit
  • posting
  • reputationlevel
  • showthread
Included Files (26):
  • ./showthread.php
  • ./global.php
  • ./includes/class_bootstrap.php
  • ./includes/init.php
  • ./includes/class_core.php
  • ./includes/config.php
  • ./includes/functions.php
  • ./includes/functions_navigation.php
  • ./includes/class_friendly_url.php
  • ./includes/class_hook.php
  • ./includes/class_bootstrap_framework.php
  • ./vb/vb.php
  • ./vb/phrase.php
  • ./includes/functions_facebook.php
  • ./includes/functions_calendar.php
  • ./includes/functions_bigthree.php
  • ./includes/class_postbit.php
  • ./includes/class_bbcode.php
  • ./includes/functions_reputation.php
  • ./includes/functions_notice.php
  • ./packages/vbattach/attach.php
  • ./vb/types.php
  • ./vb/cache.php
  • ./vb/cache/db.php
  • ./vb/cache/observer/db.php
  • ./vb/cache/observer.php 

Hooks Called (73):
  • init_startup
  • friendlyurl_resolve_class
  • init_startup_session_setup_start
  • database_pre_fetch_array
  • database_post_fetch_array
  • init_startup_session_setup_complete
  • global_bootstrap_init_start
  • global_bootstrap_init_complete
  • cache_permissions
  • fetch_postinfo_query
  • fetch_postinfo
  • fetch_threadinfo_query
  • fetch_threadinfo
  • fetch_foruminfo
  • load_show_variables
  • load_forum_show_variables
  • global_state_check
  • global_bootstrap_complete
  • global_start
  • style_fetch
  • global_setup_complete
  • showthread_start
  • showthread_getinfo
  • strip_bbcode
  • friendlyurl_clean_fragment
  • friendlyurl_geturl
  • forumjump
  • cache_templates
  • cache_templates_process
  • template_register_var
  • template_render_output
  • fetch_template_start
  • fetch_template_complete
  • parse_templates
  • fetch_musername
  • notices_check_start
  • notices_noticebit
  • process_templates_complete
  • friendlyurl_redirect_canonical
  • showthread_post_start
  • showthread_query_postids
  • showthread_query
  • bbcode_fetch_tags
  • bbcode_create
  • showthread_postbit_create
  • postbit_factory
  • postbit_display_start
  • postbit_imicons
  • bbcode_parse_start
  • bbcode_parse_complete_precache
  • bbcode_parse_complete
  • postbit_display_complete
  • memberaction_dropdown
  • tag_fetchbit
  • tag_fetchbit_complete
  • forumrules
  • navbits
  • navbits_complete
  • build_navigation_data
  • build_navigation_array
  • check_navigation_permission
  • process_navigation_links_start
  • process_navigation_links_complete
  • set_navigation_menu_element
  • build_navigation_menudata
  • build_navigation_listdata
  • build_navigation_list
  • set_navigation_tab_main
  • set_navigation_tab_fallback
  • navigation_tab_complete
  • fb_like_button
  • showthread_complete
  • page_templates