html - JavaScript element validation -


this question has answer here:

i wish check if in multiple dropdown list has been selected using javascript.

<select name="id" id="id" size=22 multiple >

and if checkboxes has been checked

<input type="checkbox" name="inst" class="asa" value="inst1">  <input type="checkbox" name="inst" class="asa" value="inst2">

try code

demo

var selectval = document.getelementbyid('id'); var selectcount = 0; var values = []; (var = 0; < selectval.options.length; i++) {   if (selectval.options[i].selected) {     selectcount++;     values.push(selectval.options[i].value);   } }

for checkbox

<input type="checkbox" name="inst" class="asa" id="check1" value="inst1">  <input type="checkbox" name="inst" class="asa" id="check2" value="inst2">  var check1 = document.getelementbyid("check1").checked; alert(check1); var check2 = document.getelementbyid("check2").checked; alert(check2);

Comments

Post a Comment

Popular posts from this blog

linux - xterm copying to CLIPBOARD using copy-selection causes automatic updating of CLIPBOARD upon mouse selection -

i've tried various ways coerce xterm (versions 285 , 292) copy selection clipboard clipboard whenever press ctrl-shift-c. promising way far has been, in ~/.xresources, put this: xterm*vt100.translations: #override \ ctrl shift <keypress> c: copy-selection(clipboard) \n\ ctrl shift <keypress> v: insert-selection(clipboard) ctrl-shift-v works perfectly, copying has nuance... if restart xterm, highlighting text puts things in primary clipboard; expected, proper, default behavior. if hit ctrl-shift-c, copies current selection clipboard clipboard. the bug, however, if highlight text after first time pressed ctrl-shift-c, you'll see highlighting copies both primary and clipboard. cannot figure out how stop xterm updating clipboard upon selection... , doesn't make sense me in first place. i said, @ specific point in time, copy selection clipboard... yet starts updating automatically upon selection after doing once... anyone have workaround...
Read more

c++ - qgraphicsview horizontal scrolling always has a vertical delta -

Image
i've subclassed qgraphicsview custom canvas used in cad application. i've reimplemented qgraphicsview::wheelevent check keyboard modifiers control key and, if control key pressed, zoom. i'm trying implement horizontal scroll when user holds shift , uses wheel. the problem i'm having horizontal scrolling always scrolls 0.279. not huge problem, hugely annoying , points else being wrong. so, here questions: is right way implement horizontal scrolling? if not, is? how eliminate delta of 0.279? thanks in advance. code , sample output below void myview::zoom(int delta) { double factor = pow(1.2, delta/abs(delta)); this->scale(factor, factor); } void myview::scrollhorizontal(int level) { qpointf center = maptoscene(viewport()->rect().center()); qdebug() << "center: " << center.x() << ", " << center.y(); centeron(qpointf(center.x() - level, center.y())); } void myview::wheelevent(qwheeleve...
Read more