样式计算的几种方式与兼容写法：getComputedStyle&currentStyle&style

export default class myUtils{
　　　　
    static getCompatibleStyle(elemOrSelect,pseudo){
        if(!elemOrSelect) return;
        if(elemOrSelect.constructor === String) elemOrSelect = document.querySelector(elemOrSelect);
        if(!pseudo) return getComputedStyle(elemOrSelect,pseudo); 
        return elemOrSelect.currentStyle ? elemOrSelect.currentStyle : getComputedStyle(elemOrSelect,null); 
    }
}

<script type="module">
        import utils from "./myUtils.js";
        console.log(utils.getCompatibleStyle("div",null).backgroundColor);
        console.log(utils.getCompatibleStyle("span","::after").display);
</script>