Upload file extension to determine the file type, add files

function Type(e){
    let text = ''
    switch(e){
        case 'application/msword':
            text = '.doc';break;
        case 'application/vnd.openxmlformats-officedocument.wordprocessingml.document':
            text = '.docx';break;
        case 'application/vnd.openxmlformats-officedocument.wordprocessingml.template':
            text = '.dotx';break;
        case 'application/vnd.ms-word.document.macroEnabled.12':
            text = '.docm';break;
        case 'application/vnd.ms-word.template.macroEnabled.12':
            text = '.dotm';break;
        case 'application/vnd.ms-excel':
            text = '.xls';break;
        case 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet':
            text = '.xlsx';break;
        case 'application/vnd.openxmlformats-officedocument.spreadsheetml.template':
            text = '.xltx';break;
        case 'application/vnd.ms-excel.sheet.macroEnabled.12':
            text = '.xlsm';break;
        case 'application/vnd.ms-excel.template.macroEnabled.12':
            text = '.xltm';break;
        case 'application/vnd.ms-excel.addin.macroEnabled.12':
            text = '.xlam';break;
        case 'application/vnd.ms-excel.sheet.binary.macroEnabled.12':
            text = '.xlsb';break;
        case 'application/vnd.ms-powerpoint':
            text = '.ppt';break;
        case 'application/vnd.openxmlformats-officedocument.presentationml.presentation':
            text = '.pptx';break;
        case 'application/vnd.openxmlformats-officedocument.presentationml.template':
            text = '.potx';break;
        case 'application/vnd.openxmlformats-officedocument.presentationml.slideshow':
            text = '.ppsx';break;
        case 'application/vnd.ms-powerpoint.addin.macroEnabled.12':
            text = '.ppam';break;
        case 'application/vnd.ms-powerpoint.presentation.macroEnabled.12':
            text = '.pptm';break;
        case 'application/vnd.ms-powerpoint.presentation.macroEnabled.12':
            text = '.potm';break;
        case 'application/vnd.ms-powerpoint.slideshow.macroEnabled.12':
            text = '.ppsm';break;
        case 'image/jpeg':
            text = '.jpeg';break;
        case 'image/x-icon':
            text = '.icon';break;
        case 'image/png':
            text = '.png';break;
        case 'image/gif':
            text = '.gif';break;
    }
    return text;
}