JS动态添加/删除css文件

function loadStyles (file) {
    var fileref = document.createElement("link")
    fileref.setAttribute("rel", "stylesheet")
    fileref.setAttribute("type", "text/css")
    fileref.setAttribute("href", file)
}
// 使用，file是css文件路径
loadStyles('./test.css')

function addStyle(file){
   $('head').append('<link href=' + file + ' rel="stylesheet" type="text/css">')
}

function removeStyles (file) {
    var filename = file;
    var targetelement = "link";
    var targetattr = "href";
    var allsuspects = document.getElementsByTagName(targetelement);
    for (var i = allsuspects.length; i >= 0; i--) {
        if (allsuspects[i] && allsuspects[i].getAttribute(targetattr) != null && allsuspects[i].getAttribute(
            targetattr).indexOf(filename) != -1) {
            allsuspects[i].parentNode.removeChild(allsuspects[i])
        }
    }
}
// 使用，file是css文件路径
removeStyles('./test.css')