[javascript] Get elements by attribute when querySelectorAll is not available without using libraries?

Try this - I slightly changed the above answers:

var getAttributes = function(attribute) {
    var allElements = document.getElementsByTagName('*'),
        allElementsLen = allElements.length,
        curElement,
        i,
        results = [];

    for(i = 0; i < allElementsLen; i += 1) {
        curElement = allElements[i];

        if(curElement.getAttribute(attribute)) {
            results.push(curElement);
        }
    }

    return results;
};

Then,

getAttributes('data-foo');