Limit the number of text bytes js code_form effects

When working on a project, I write a piece of js for everyone. Regarding the problem of limiting the number of characters in text, it is often used in actual development; the main problem occurs in the restriction of Chinese. The following code solves the verification problem of limiting the number of bytes; just save this code to a js file and Introduce it into the verification page and you can use it! At the same time, I hope you will give me your strong support and valuable opinions. I will publish more good articles in my spare time in the future, thank you! !


/*
value: value;
byteLength: database byte length
title: field Chinese name
attribute: attribute name
Usage instructions:

Add (1) onkeyup="limitLength(this.value,100,'name','name')"
(2) id="name" or [struts tag] styleId="name"
Note: The id name and attribute name must be the same

Example: <br><br> or <br><br><input> <br><br>*/ <br><br><br><br>function limitLength(value, byteLength, title, attribute) { <br> var newvalue = value.replace(/[^x00-xff]/g, "**"); <br> var length = newvalue.length; <br><br> //When the number of bytes filled in is less than the set number of bytes <br> if (length * 1 return; <br> }  <br> var limitDate = newvalue.substr(0, byteLength); <br> var count = 0; <br> var limitvalue = ""; <br> for (var i = 0; i var flat = limitDate.substr(i, 1); <br> if (flat == "*") { <br> count ; <br> } <br> } <br> var size = 0; <br> var istar = newvalue.substr(byteLength * 1 - 1, 1);//Whether the check point is "×" <br><br> //if the base point is ×; determine if there is × within the base point Is it an even number or an odd number? <br> if (count % 2 == 0) { <br> limitvalue = value.substr (0, size); <br> } else { <br>                                                                                                                        .substr( 0, size); <br> } <br> alert(title "Maximum input" byteLength "bytes (equivalent to " byteLength /2 " Chinese characters)! "); <br> document.getElementById(attribute).value = limitvalue; <br> return; <br>}