大约有 37,000 项符合查询结果（耗时：0.0425秒） [XML]
Which equals operator (== vs ===) should be used in JavaScript comparisons?
...n the third rule)
Now it becomes interesting:
var a = "12" + "3";
var b = "123";
alert(a === b); // returns true, because strings behave like value types
But how about this?:
var a = new String("123");
var b = "123";
alert(a === b); // returns false !! (but they are equal and of the same type)
I...
Summarizing multiple columns with dplyr? [duplicate]
...brary(dplyr)
library(purrrlyr)
library(data.table)
library(bench)
set.seed(123)
n <- 10000
df <- data.frame(
a = sample(1:5, n, replace = TRUE),
b = sample(1:5, n, replace = TRUE),
c = sample(1:5, n, replace = TRUE),
d = sample(1:5, n, replace = TRUE),
grp = sample(1:3, n, replac...
How does facebook, gmail send the real time notification?
...JAX, it'll take a lot of the cross-compability problems away. In terms of PHP, you could simply poll an event log database table in your PHP script, and only return to the client when something happens? There are, I expect, many ways of implementing this.
Implementing:
Server Side:
There appear ...
How do I create a comma-separated list from an array in PHP?
...ut it's always a pain having to take off the final comma. Is there an easy PHP way of doing it?
12 Answers
...
How can I count all the lines of code in a directory recursively?
We've got a PHP application and want to count all the lines of code under a specific directory and its subdirectories. We don't need to ignore comments, as we're just trying to get a rough idea.
...
Facebook Architecture [closed]
...g/post/358
You can use HipHop yourself:
https://github.com/facebook/hiphop-php/wiki
But if you ask me it's a very ambitious and probably time wasting task. Hiphop only supports so much, it can't simply convert everything to C++. So what does this tell us? Well, it tells us that Facebook is NOT full...
Write a number with two decimal places SQL server
...ters to display, and the number of decimal places to display
Select Str(12345.6789, 12, 3)
displays: ' 12345.679' ( 3 spaces, 5 digits 12345, a decimal point, and three decimal digits (679). - it rounds if it has to truncate, (unless the integer part is too large for the total size, in whic...
JavaScript isset() equivalent
In PHP you can do if(isset($array['foo'])) { ... } . In JavaScript you often use if(array.foo) { ... } to do the same, but this is not exactly the same statement. The condition will also evaluate to false if array.foo does exists but is false or 0 (and probably other values as well).
...
php static function
I have a question regarding static function in php.
6 Answers
6
...
download file using an ajax request
...ownload. Instead, you could use a success function to navigate to download.php. This will open the download prompt but won't change the current page.
$.ajax({
url: 'download.php',
type: 'POST',
success: function() {
window.location = 'download.php';
}
});
Even though this ...