删除特殊字符和限定用户输入长度的示例代码

/检查非法字符并检验字符长度

function checkSpeChar(obj, byteLength, title) {

var value = document.getElementById(obj).value;

value = value.replace(/(^\s*)/g, "").replace(/(\s*$)/g, "");

var ret = (/[-|;|,|\/|\(|\)|\[|\]|\}|\{|%|@|\*|!|\']/.test(value));

var arr = ["@", "#", "$", "%", "^", "&", "*", "<", ">", "/", "\\", "\'", "'", ".", ":", "?", "[", "]", ";", "-", "、", "(", ")", "_", "\"", "~", "insert", "delete", "update", "select"];

value = value.toLowerCase();

for (var i = 0; i < arr.length; i++) {

if (value.indexOf(arr[i].toLowerCase()) >= 0) {

ret = true;

}

}

if (ret == true) {

top.LSAlert("内容中含非法字符，请重新输入！");

document.getElementById(obj).value = '';

return;

}

limitLength(value, byteLength, title, obj);

}

//验证输入字符长度

function limitLength(value, byteLength, title, attribute) {

value = value.replace(/\r/g, " ").replace(/\n/g, " "); //回车换行分别替换两个空格

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.substr(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×;

if (count % 3 == 0) {

size = count / 3 + (byteLength * 1 - count);

limitvalue = value.substr(0, size);

}

else if (count % 3 == 1) {

size = (count - 1) / 3 + (byteLength * 1 - count);

limitvalue = value.substr(0, size);

}

else if (count % 3 == 2) {

size = (count - 2) / 3 + (byteLength * 1 - count);

limitvalue = value.substr(0, size);

}

//top.LSAlert(title + "最大输入" + byteLength + "个字节！");

document.getElementById(attribute).value = limitvalue;

return;

}