javascript foo.substr 给出“不是函数”错误
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foo.substr gives "Is not a function" error
提问by Clay
I'm using Jquery's datepicker plugin (which works fine). Then I need to extract the "day of the week" from the picked date.
我正在使用 Jquery 的 datepicker 插件（工作正常）。然后我需要从选择的日期中提取“星期几”。
When using foo.substring(0,3)to assign the first three characters of the datepicker('getDate')I get: TypeError foo.substr is not a function.
当foo.substring(0,3)用于分配datepicker('getDate')I get的前三个字符时：TypeError foo.substr is not a function.
$(function () {
$("#textDatepicker").datepicker();
});
function selectedDay() {
var foo = $("#textDatepicker").datepicker('getDate');
//IF USED.... alert(foo);
//retuens (for example).....
//"Thu Jul 18 00:00:00 GMT-0400 (Eastern Standard Time)"
var weekday = foo.substr(0, 3)
document.getElementById("dayofweek").innerHTML = "The day of the week selected is: " + weekday;
}
<head>
<script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript"></script>
<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
<script src="https://jquery-blog-js.googlecode.com/files/SetCase.js" type="text/javascript"></script>
<link rel="stylesheet" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css"/>
</head>
<body>
Select Date: <input type="text" id="textDatepicker" onchange="selectedDay();">
<br><br>
<span id="dayofweek">Selected day of week replaces this</span>
</body>
I have also pasted at: jsfiddle
我也粘贴在：jsfiddle
Any help would be appreciated.. Thanks in advance...
任何帮助将不胜感激.. 提前致谢...
回答by adeneo
var foo = $("#textDatepicker").datepicker('getDate');
returns a Date object, not a string, and has no method substr()
返回一个 Date 对象，而不是一个字符串，并且没有方法 substr()
You can solve it by removing that unsightly inline event handler and doing :
您可以通过删除难看的内联事件处理程序并执行以下操作来解决它：
$("#textDatepicker").datepicker({
onSelect: function() {
var date = $(this).datepicker('getDate');
var day = $.datepicker.formatDate('DD', date);
$('#dayofweek').html(day);
}
});
回答by Jonast92
$("#textDatepicker").datepicker('getDate');
is an object. You can't take the substring of an object with substr.
是一个对象。您不能使用 substr 获取对象的子字符串。
回答by sunshine
foo.substr(0,3) is the culprit. It returns a date object and you can do substr on a date object. You could fix the problem by using the code below
foo.substr(0,3) 是罪魁祸首。它返回一个日期对象，您可以对日期对象执行 substr。您可以使用以下代码解决问题
function selectedDay() {
var foo = $("#textDatepicker").datepicker('getDate');
//IF USED.... alert(foo);
//retuens (for example).....
//"Thu Jul 18 00:00:00 GMT-0400 (Eastern Standard Time)"
var weekday = foo.getDay();
document.getElementById("dayofweek").innerHTML = "The day of the week selected is: " + weekday;
}
function selectedDay() {
var foo = $("#textDatepicker").datepicker('getDate');
//IF USED.... alert(foo);
//retuens (for example).....
//"Thu Jul 18 00:00:00 GMT-0400 (Eastern Standard Time)"
var weekday = foo.getDay();
document.getElementById("dayofweek").innerHTML = "The day of the week selected is: " + weekday;
}
回答by Ismael ozil
called the toString();method before calling the subString();like foo.toString().subString(start,length);Worked for me
被称为toString();调用方法之前subString();一样foo.toString().subString(start,length);对我来说有效
