javascript parseInt is broken
I was debugging some strange errors in a date conversion function I was writing, and I stumbled upon something that amazed me... a strange bug in parseInt
>>>parseInt('06')
6
>>>parseInt('07')
7
>>>parseInt('08')
0
>>>parseInt('09')
0
>>>parseFloat('08')
8
>>>parseFloat('09')
9
Clearly for the strings '08' and '09' parseInt fails to return the right value. One workaround is easy, use parseFloat.
Why does this happen and where should I report this? I find it extremely odd that it happens in both Firefox and Internet Explorer 6 & 7; there must be some explanation right?
You can test it out for yourself using the FireBug javascript console), or by using one of these two links
alert(parseInt('07')+' == 7 ?')
alert(parseInt('08')+' == 8 ?')
Ok, Ok, so now that I explained how you would expect it to work (and clearly how I expected it to work) I'm going to answer my own question (yes I hate it when I do that too)
The problem is with how parseInt guesses the base of your number. Read the parseInt spec. Instead of always defaulting to base 10, it tries to guess, and if the first character is '0' it thinks you want to parse as an octal number, and if it starts with '0x' it thinks you want hexadecimal.
So, the solution is either to use parseFloat or to always specify your base.
Defaults that change on their own can't be trusted.
>>>parseInt('08',10)
8
1、插入排序->直接插入法排序
function InsertSort(arr) { //插入排序->直接插入法排序
var st = new Date();
var temp, j;
for(var i=1; i<arr.length; i++) {
if((arr[i]) < (arr[i-1])) {
temp = arr[i];
j = i-1;
do {
arr[j+1] = arr[j];
j--;
}
whil ......
尽管 JavaScript 历史上使用冗长而令人生厌的代码块来标的特定浏览器的时期已经结束了，但是偶尔使用一些简单的代码块和对象检测来确保一些代码在用户机器上正常工作依然是必要的。
这篇文章中，我会略述一下 Internet Explorer 和 Firefox 在 JavaScript 语法上不同的几 个方面。
......
通过分析各类浏览器的userAgent信息，不难得出分辨各类浏览器及其版本的正则表达式。而且，对浏览器类型的判断和版本的判断完全可以合为一体地进行。于是，我们可以写出下面的代码：
<script type="text/javascript">
......
在JavaScript中，变量中可以存储的值主要有两种类型：原始值（primitive value）和引用值（reference value）。前者通常是固定而又简单的数据，存储在栈（stack）中，而后者则是比较大的对象，存储在堆（heap）中，而对于后者的调用，是通过存储在栈中的指针来完成的。原始类型有五种：Number、String、Boolean、Null和Unde ......
