如何验证此字符串在Javascript中不包含任何特殊字符？

Question

I have a dynamic string like this which may look like:

"69.43.202.97"                 OR               "ngs.pradhi.com"

I want to validate these string contains only numbers, english alphabets and "." . I want to validate this in front end using java script. I thought of using regular expression like this:

function validatePath() {
    var path = document.getElementById('server_path').value;
    path.match([a-z][0-9])  //or something like this
}

If the path is invalid despite of displaying the alert box I just want to show the error below the text field as soon as the user fills the server path. How can I do that?

My full javascript function looks like this:

function validatePath() {
    var path = document.getElementById('server_path').value;
    if (path.search(":") == -1){
        alert("Invalid server path");
    }
    else{
        var host_name = path.split(":")[0]
        if host_name.match("^[a-zA-Z0-9.]*$")) {}

    }

}

Answer 1

try path.match("^[a-zA-Z0-9.]*$")

EDIT: var regex = new RegExp("^[a-zA-Z0-9.]*$"); if(regex.test(host_name)){} var regex = new RegExp("^[a-zA-Z0-9.]*$"); if(regex.test(host_name)){}

Answer 2

您可以使用/^[a-zA-Z0-9.]*$/.test(path) ，它将返回true或false

Answer 3

不同的是，替换方法：

if(path.replace(/^[a-z\d.]*$/i,"")=="")

Answer 4

You can do the check (including port presence) with a regex like this:

^[a-zA-Z0-9\.]+:[0-9]+$

(Note the + instead of * to account for empty path or port (they are not allowed).)

If you are using HTML5, consider the newly introduced "pattern" and "required" attributes, which can posdibly save you some JS code.

See this short demo for an illustration of both technics.

Some links you might find useful:

• Regular Expressions
• The HTML5 "pattern" attribute
• The HTML5 "required" attribute