做项目时自己写一段js给大家。关于文本限制字数的问题,在实际开发中经常用到;主要问题出现在对中文的限制,下面代码就解决关于限制
="text" name="explain" id="explain" onkeyup="limitLength(value,5,'语义说明','explain')" >
function limitLength(value, byteLength, title, attribute) {
VAR newvalue = value.replace(/[^\x00-\xff]/g, "**");
var length = newvalue.length;
//当填写的字节数小于设置的字节数
if (length * 1 <=byteLength * 1){
return;
}
var limitDate = newvalue.s
ubstr(0, byteLength);
var count = 0;
var limitvalue = "";
for (var i = 0; i < limitDate.length;
i++) {
var flat = limitDate.substr(i, 1);
if (flat
== "*") {
count++;
}
}
var size = 0;
var istar = newvalue.substr(byteLength * 1 - 1, 1);//校验点
是否为“×”
//if 基点是×; 判断在基点内有×为偶数还是
奇数 if (count % 2 == 0) {
//当为偶数时
size = count / 2 + (byteLength * 1 - count);
limitvalue = value.substr(0, size);
} else {
//当为奇数时
size = (count - 1) / 2 + (byteLength * 1 - count);
limitvalue = value.substr(0, size);
}
alert(title + "最大输入" + byteLength + "个字节(相当于"+byteLength /2+"个汉字)!");
document.getElementById(attribute).value = limitvalue;
return;
}