javascript - 使用正则表达式在字符串中查找不匹配的字符

Question

当文本输入/粘贴文本时，我必须在文本区域中找到并向用户显示键盘字符以外的任何特殊字符，下面我解释了我要做什么!请尽快帮助我？

if ($(txtMessage).val().trim() != "") {
         var pattern = "^[a-zA-Z0-9~`!@#$%^&*()_+-={}|:;<>,.?\/']+$";
         for(var i=0;i<$(txtMessage).val().length;i++){
             var subStr=$(txtMessage).val().substring(0, i);
             if(!subStr.match(pattern)){
                 $('#customDailogBox')
                    .text(
                            "You have entered or paste "+subStr.substring(i, i)+"input  characters are not supported characters!!!..");
             }
         }

Answer 1

改变你的循环条件和子字符串函数

 for(var i=1;i=<$(txtMessage).val().length;i++){
         var subStr=$(txtMessage).val().substr(i,1);
         if(!subStr.match(pattern)){
             $('#customDailogBox').text("You have entered or paste "+subStr.substring(i, i)+"input  characters are not supported characters!!!..");
         }
}

或者你也可以使用正则表达式对整个字符串进行一次匹配

var unmatched_characters = $(txtMessage).val().match(/[^a-zA-Z0-9~`!@#$%^&*()_+-={}|:;<>,.?\/']/g);
if (unmatched_characters.length>0){
     $('#customDailogBox').text("You have entered or paste some characters that are not supported !!!..");
}