从动态表单获取更大价值的输入

Question

I have the below HTML and I want to use jQuery to find out all the input elements with an id beginning with a that have a value bigger than id beginnging with b . For this example, the result below would select it will be #a2 and #a3 .

<div class="form">
    <input id="a1" value="1" />
</div>
<div class="form">
    <input id="b1" value="5" />
</div>

<div class="form">
    <input id="a2" value="3" />
</div>
<div class="form">
    <input id="b2" value="1" />
</div>

<div class="form">
    <input id="a3" value="2" />
</div>
<div class="form">
    <input id="b3" value="1" />
</div>

<div class="form">
    <input id="a4" value="1" />
</div>
<div class="form">
    <input id="b4" value="5" />
</div>

...

Answer 1

You can use .filter() with condition that compares both values:

$('[id^=a]').filter(function(){
   return parseInt($(this).val(),10) > parseInt($(this).parent().next().find('input').val(),10) 
});

Working Demo

Update: To get the id of elements that matches the condition

$('[id^=a]').filter(function(){
    return parseInt($(this).val(),10) > parseInt($(this).parent().next().find('input').val(),10) 
}).map(function(){
    return $(this).attr("id");
}).get().join("-")

Demo

Answer 2

You can use the 'attribute begins with' selector and filter() to achieve this:

var $a = $('[id^="a"]').filter(function() {
    var aVal = parseInt($(this).val(), 10);
    var bVal = parseInt($(this).closest('.form').next().find('input').val(), 10);
    return aVal > bVal;
});

The $a variable will now contain the a elements with a higher value than their immediate sibling b .

How to get all the number on the end of id a="" into an array?

To do this you can use map() :

var aValues = $a.map(function() {
    return this.value;
}).get();
console.log(aValues); // shows all the larger A values gathered.