How to determine if a js string contains numbers and special characters?

In our daily work, we use javaScript to determine whether a string contains numbers and "-". In some form submission places, this is a more useful general judgment. There are several different methods collected here

1. Regular expression method to determine whether it is a number, including determining a positive integer:

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function checkRate(input) { var re = /^[0-9]+.?[0-9]*$/; //判断字符串是否为数字,//若判断正整数，则后边是：/^[1-9]+[0-9]*]*$/ if (!re.test(input.rate.value)) { alert("请输入数字(例:0.02)"); input.rate.focus(); return false; } }

2. Ordinary JS function method:

function BASEisNotNum(theNum) { if (BASEtrim(theNum)=="") return true; for(var i=0;i"9") return true; } return false; }

3. Determine whether it is a positive number, that is Positive integer:

function BASEisNotInt(theInt) { theInt=BASEtrim(theInt); if ((theInt.length>1 && theInt.substring(0,1)=="0") || BASEisNotNum(theInt)){ return true; } return false; }

4. Determine whether the string is composed of numbers and other symbols, such as "-":

function ismonth(str) { for(ilen=0;ilen '9' ) { if((str.charAt(ilen)!='-')) return false; } } return true; }

5. Determine whether it is a floating point number:

function BASEisNotFloat(theFloat) { len=theFloat.length; dotNum=0; if (len==0) return true; for(var i=0;i"9") && oneNum!=".") || dotNum>1) return true; } if (len>1 && theFloat.substring(0,1)=="0"){ if (theFloat.substring(1,2)!=".") return true; } return false;

isNaN(expression:Object) : Boolean. Computes a parameter and returns true if the value is NaN (not a number). This function can be used to check whether a mathematical expression evaluates successfully to a number.

is often used like this in submission forms:

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