So I have a script block:
<script>
var totalPopulation = 0;
for(xxxxx){
totalPopulation = totalPopulation + xxx
}
</script>
<tr>
<input type="text" name="censusPop" value=totalPopulation/>
<tr>
I'm still quite green to javascript. But is there a way to assign the value of a variable in a script block to a HTML element like input type? I know that the code is unreachable.
hope it will help you to understand how javascript work
<html>
<head>
<script>
var totalPopulation = 0;
function addAndShowPopulation(population) {
totalPopulation = totalPopulation + population;
var input_tag = getTag('my_input_id');
input_tag.value = totalPopulation;
}
function startAdding() {
addAndShowPopulation(10);
setTimeout( function(){startAdding();},1000);
}
function getTag(id) {
return document.getElementById(id);
}
</script>
</head>
<body onload="startAdding();">
<div>
<input type="text" id="my_input_id" name="censusPop" value="" placeholder="Total Population"/>
</div>
</body>
</html>
Yes, you just have to give an id to the input, for instance "id = my_input_id"; Then, in the javascript, just write :
$("my_input_id").value=totalPopulation;
That's how ajax works: find html elements ids and fill them dinamically using javascript values.
Just be carefull that the html in read before the JS. If not, $("my_input_id") will return Null
More so, you need to do something like this:
<tr>
<td>
<input type="text" id="censusPop" name="censusPop" value=""/>
<td>
<tr>
<!-- Other stuff -->
<script>
var totalPopulation = 10;
// or for loop, or whatever here.
var censusText = document.getElementById('censusPop');
censusText.value = totalPopulation;
</script>
</body>
HTML and JavaScript can interact, but not directly like that. The best thing to do is use <script> tags to setup code that updates the browser DOM. By putting the <script> tags after the HTML, usually at the bottom of the <body> tag, you allow the browser a chance to create the elements before you actually try to use them.
Another note: <tr> tags should contain <td> tags, it's the difference between a row and a column.
If you need to do multiple DOM manipulations, I'd suggest using jQuery is the proper way.
<tr>
<input id="censusPop" type="text" name"censusPop" value=""/>
</tr>
<script src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
<script>
// make sure, the code is executed when the DOM is ready
$(function () {
// grab the input element by its ID
var $input = $('#censusPop'),
totalPopulation = 0;
// do your population calculations
totalPopulation = ....;
// assign the value to the input element
$input.val(totalPopulation);
});
</script>
