How to filter uploaded file formats using javascript/jquery_jquery

Copy code The code is as follows: .errorInfo{ color:red; padding-left:5px; } --> color:red; padding-left:5px; } $(function(){ $("#DataReport").click(function(){ //The uploaded file cannot be empty, and the format must be xsl and xlsx var flag=true; var fileObject=$("input[name='file']"); var filepath=$("input[name='file']").val(); if(filepath ==undefined||$.trim(filepath)==""){ fileObject.focus().next().text("Please choose to upload a file!"); flag=false; }else{ var fileArr=filepath.split("\"); var fileTArr=fileArr[fileArr.length-1].toLowerCase().split("."); var filetype =fileTArr[fileTArr.length-1]; if(filetype!="xls"&&filetype!="xlsx"){ fileObject.focus().next().text("The uploaded file must be Excel File! "); flag=false; }else{ fileObject.next().text(""); } } //Proceed Other related checks if(flag){ alert("File uploaded successfully"); } }); }); / / --> Note: If you add the jquery import statement in the head, the blog will still filter out the imported js files. How to filter uploaded file formats in JavaScript: Copy code The code is as follows: "http://www.w3.org/TR/html4/loose.dtd"> .errorInfo{ color:red; padding-left:5px; } --> .errorInfo{ color:red; padding-left:5px; } function validateFile(){ var flag=true; var fileObject=document.getElementById("file" ); var errorObject=document.getElementById("error"); var filepath=fileObject.value; if(filepath==undefined||filepath==""){ fileObject. focus(); errorObject.innerText="Please select a file to upload!"; flag=false; }else{ var fileArr=filepath.split("\"); var fileTArr=fileArr[fileArr.length-1].toLowerCase().split("."); var filetype=fileTArr[fileTArr.length-1]; if(filetype!="xls"&&filetype !="xlsx"){ fileObject.focus(); errorObject.innerText="The uploaded file must be an Excel file! "; flag=false; }else{ errorObject.innerText=""; } } //Perform other related verifications if(flag) { alert("File uploaded successfully"); } } // --> &lt ;span id="error" class='errorInfo'>