如何使用JQuery验证文本

Question

I just want to ask on how to validate input text using jQuery

I want to determine if input text has a 'AF' character

Thank you

Answer 1

If you just mean validating that a string has "AF" inside of it, you can simply use String.indexOf , eg

var someText = "AFTER";
if (someText.indexOf("AF") >= 0) {
    // Text has "AF" in it...
}

If you want to validate an input field, for instance, you can use jQuery to get the value of the field, and perform the same check afterwards, eg

var someText = $('#myInput').val();
if (someText.indexOf("AF") >= 0) {
    // Input field has "AF" in it...
}

You can pair this with jQuery's .keyup to validate the text as the user types. See the fiddle below for an example:

https://jsfiddle.net/aoldershaw/xg4cwyjh/1/

Answer 2

Use regExpression

in these expression to cheak the hole text.

var yourInput = $('#myInput').val();
//with caseSensitive
var isMatch = yourInput.match(/AF/g);
alert(isMatch); // If return 'null' the text not present.

//withOut caseSensitive
var isMatch = yourInput.match(/AF/gi);
alert(isMatch); // If return 'null' the text not present.