Common JavaScript Functions

//使用截取字符串的方法移除其前导空格,制表符,回车,换行. function trimStart(str) { var leadingCharacters = new String(' ' + '/t/n/r'); var originalString = new String(str); var noLeadingCharacters; if (leadingCharacters.indexOf(originalString.charAt(0)) != -1) { // We have a string with leading blank(s)... var j=0, i = originalString.length; // Iterate from the far left of string until we // don't have any more whitespace... while (j < i && leadingCharacters.indexOf(originalString.charAt(j)) != -1) { j++; } // Get the substring from the first non-whitespace // character to the end of the string... noLeadingCharacters = originalString.substring(j); } return noLeadingCharacters; } //使用截取字符串的方法移除其尾部空格,制表符,回车,换行. function trimEnd(str) { var trailingCharacters = new String(' ' + '/t/n/r'); var originalString = new String(str); var noTrailingCharacters; if (trailingCharacters.indexOf(originalString.charAt(originalString.length-1)) != -1) { // We have a string with trailing blank(s)... var i = originalString.length - 1; // Iterate from the far right of string until we // don't have any more whitespace... while (i >= 0 && trailingCharacters.indexOf(originalString.charAt(i)) != -1) { i--; } // Get the substring from the front of the string to // where the last non-whitespace character is... noTrailingCharacters = originalString.substring(0, i+1); } return noTrailingCharacters; } //统计与限制输入字符数 //commentId--接受字符输入元素的Id //limitId--显示字符数元素(如label元素)的Id //count--最大允许字符数 //如<textarea rows="4" cols="43" title="Please enter !" id="textLimited" runat="server" // onkeyup="return limiter('textLimited','tip',100)" // onkeypress="return limiter('textLimited','tip',100)"/> // 还可以输入<label id="tip">100</label>个字符 function limiter(commentId,limitId,count) { var text = document.getElementById(commentId).value; var len = text.length; if(len > count) { text = text.substring(0,count); document.getElementById(commentId).value =text; return false; } document.getElementById(limitId).innerHTML = count-len; } //filter non-number(keypress) function filterNaN(e) { //8：退格键、46：delete、37-40： 方向键 //48-57：小键盘区的数字、96-105：主键盘区的数字 //110、190：小键盘区和主键盘区的小数 //189、109：小键盘区和主键盘区的负号 //<input type="text" id="test" onkeypress="return filterNaN(event)" // style="IME-MODE:disabled"/ onpaste="return false;"> var keynum; var keychar; var numcheck; keychar = window.event; if(window.event) // IE { keynum = event.keyCode; } else if(e.which) // Netscape/Firefox/Opera { keynum = e.which; alert(keynum); if( keynum == 8 || keynum == 46 || (keynum>37 && keynum <40)) { return true; } } keychar = String.fromCharCode(keynum); numcheck = //d/; keynum = numcheck.test(keychar); return keynum; } //通过指定的HTML Element Name(insensitive)获取所有元素对象,以数组返回 function getElementsBySpecifiedName(name) { var elements = new Array(); if(document.all) //for Mozilla Browsers { for(var index = 0;index < document.all.length;index++) { if( document.all[index].name != null && document.all[index].name.toLowerCase() == name.toLowerCase()) { elements.push(document.all[index]); } } } else //for IE { var allElements = document.getElementsByTagName("body")[0].getElementsByTagName("*"); for(var i = 0;i < allElements.length;i++) { if(allElements[i] != null && allElements[i].name && allElements[i].name.toLowerCase() == name.toLowerCase()) { elements.push(allElements[i]); } } } return elements; }