JSFiddle - React, Tailwind, and code Playground

HTML

<a href="hey"></a>

JavaScript

var getElementsByAttribute = function(attr, value) {
        if ('querySelectorAll' in document) {
            return document.querySelectorAll( "["+attr+"="+value+"]" )   
        } else {
            var els = document.getElementsByTagName("*"),
                result = []
    
            for (var i=0, _len=els.length; i < _len; i++) {
                var el = els[i]
                
                if (el.hasAttribute(attr)) {
                    if (el.getAttribute(attr) === value) result.push(els[i])
                }
            }
        
            return result
        }
    }
    
    console.log( getElementsByAttribute("href","hey") )