Reports

Also interesting in this case (Sorry if somebody also wrote a similar answer. Didn't see it. Works in my Jquery also):

If I want to retrieve the width property value of a progress bar

Here is my HTML

<div class="progress">
    <div class="progress-bar" role="progressbar" aria-valuenow="0" aria-valuemin="0"  aria-valuemax="100"> 40%</div>
</div>

My CSS

.progress-bar {
    width: 40%;
}

My Javascript

var item = document.querySelector('.progress-bar');
item.textContent = getDefaultStyle(item, 'width');

function getDefaultStyle(element, prop) {
    var parent = element.parentNode,
        computedStyle = getComputedStyle(element),
        value;
    parent.style.display = 'none';
    value = computedStyle.getPropertyValue(prop);
    parent.style.removeProperty('display');
    return value;
}

Get the integer value

var width = parseInt(item.textContent.replace("%",'')); 
echo width
//Outputs 40

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