You could use a regular expression replace:

    str = str.replace(/ +(?= )/g,&#39;&#39;);

Credit: The above regex was taken from https://stackoverflow.com/questions/1981349/regex-to-replace-multiple-spaces-with-a-single-space



There are a lot of options for regular expressions you could use to accomplish this.  One example that will perform well is:

    str.replace( /\s\s+/g, &#39; &#39; )

See this question for a full discussion on this exact problem: https://stackoverflow.com/questions/1981349/regex-to-replace-multiple-spaces-with-a-single-space

you all forget about quantifier n{X,} http://www.w3schools.com/jsref/jsref_regexp_nxcomma.asp

here best solution

    str = str.replace(/\s{2,}/g, &#39; &#39;);

You can also replace without a regular expression.

    while(str.indexOf(&#39;  &#39;)!=-1)str.replace(&#39;  &#39;,&#39; &#39;);

I&#39;m trying to develop an app that prevents a user from getting to a specified app without a password. The scenario is...

1. user clicks on &quot;Email&quot; app (for example)
2. my app detects launch of an app
3. my app confirms it is the &quot;Email&quot; app
4. my app opens a view over the top, asking for a password
5. user enters a password, if correct, my app disappears, leaving the &quot;Email&quot; app on top

I&#39;m ok doing the rest of it, just part 2 is puzzling me, and after many days reading up on Broadcast Intents etc and trying to listen for &quot;android.intent.action.MAIN&quot; etc in my trial projects I can&#39;t seem to detect when an app other than mine is started.

Can anyone help? Am I going about it the right way, in looking for new apps broadcasting an intent to start, or should I be reading the system log for new intents, or doing something in native code? 

Any pointers would help, even if you can&#39;t answer it fully I&#39;ll be able to do some more research. Thanks a lot. Ian

Android, Detect when other apps are launched

I am struggling with the following issue. I need to generate reports that consists of a collection of charts. All these charts, except one, are made using Matplotlib default backend (TkAgg). One chart needs to be made using the Cairo backend, the reason is that I am plotting an igraph graph and that can only be plotted using Cairo. 

The issue is that I cannot change backends on the fly, for example the following does not work:    
    `matplotlib.pyplot.switch_backend(&#39;cairo.png&#39;)`
(I know that the switch_backend functionality is experimental)

and I have also tried `matplotlib.use(&quot;cairo.png&quot;)` but this leads to import problems as the `matplotlib.use(&quot;cairo.png&quot;)` statement should come before importing `matplotlib.pyplot`. 
but I need two different backends over the course of the life of the script. 

So my question is does someone have a code snippet that shows how to switch the backend in Matplotlib?


Thanks so much!

UPDATE:
I have written a snippet that loads matplotlib, shows the default backend, unloads matplotlib, reloads it and changes the backend:

    import matplotlib
    import matplotlib.pyplot as plt
    import sys
    print matplotlib.pyplot.get_backend()

    modules = []
    for module in sys.modules:
        if module.startswith(&#39;matplotlib&#39;):
            modules.append(module)

    for module in modules:
        sys.modules.pop(module)

    import matplotlib
    matplotlib.use(&quot;cairo.png&quot;)
    import matplotlib.pyplot as plt

    print matplotlib.pyplot.get_backend()

but is this really the way to do it? 


UPDATE 2: I had some serious brain freeze yesterday... The simple and most obvious solution is to use the Cairo backend for all charts and not to switch the backend at all :)

UPDATE 3: Actually, it&#39;s still an issue so anybody who knows how to dynamically switch matplotlib backends....please post your answer. 

How to change backends in matplotlib / Python

How can I automatically replace all instances of multiple spaces, with a single space, in Javascript?

I&#39;ve tried chaining some `s.replace` but this doesn&#39;t seem optimal.

I&#39;m using jQuery as well, in case it&#39;s a builtin functionality.

Remove all multiple spaces in Javascript and replace with single space

How can I automatically replace all instances of multiple spaces, with a single space, in Javascript?
I've tried chaining some <code>s.replace</code> but this doesn't seem optimal.
I'm using jQuery as well, in case it's a builtin functionality.

Is there a way to determine the number of available CPU cores in JavaScript, so that you could adjust the number of web workers depending on that?

Get number of CPU cores in JavaScript?

Is it possible in `JavaScript` to do something like `preg_match` does in `PHP` ?

I would like to be able to get two numbers from string:

    var text = &#39;price[5][68]&#39;;

into two separated variables:

    var productId = 5;
    var shopId    = 68;

Edit:
I also use `MooTools` if it would help.


preg_match in JavaScript?

The question is pretty much all in the title.

Is it possible (and how?) to open a popup with javascript and then detect when the user closes it?

I am using jquery within the project so a jquery solution would be good. Cheers!

is it possible to open a popup with javascript and then detect when the user closes it?

Let&#39;s assume we have the following JavaScript object:

    ahash = {&quot;one&quot;: [1,2,3], &quot;two&quot;: [4,5,6]}

Is there a function that returns the first key name for the given object?

From the example above I want to get `one` as a result of that function.

Get the first key name of a JavaScript object

How do you get the *currently* selected `&lt;option&gt;` of a `&lt;select&gt;` element via JavaScript?

How do you get the currently selected &lt;option&gt; in a &lt;select&gt; via JavaScript?

Trying to find `div` element with `id=&quot;result&quot;` in returned data from `.ajax()` using `.find()`. Unfortunately, `alert(result)` doesn&#39;t return `div#result`.

Here is my code:

    $.ajax({
        url: url, 
        cache: false,
        success: function(response) {
            result = $(response).find(&quot;#result&quot;);
            alert(response); // works as expected (returns all html)
            alert(result); // returns [object Object]
        }
    });




jQuery .find() on data from .ajax() call is returning &quot;[object Object]&quot; instead of div

I have a small problem with jQuery `$.ajax()` function.

I have a form  where every click on the radio button or selection from the dropdown menu creates a session variable with the selected value.

Now - I have one of the dropdown menus which have 4 options - the first one (with label None) has a `value=&quot;&quot;` other have their ids.

What I want to happen is to None option (with blank value) to remove the session and other to create one, but only if session with this specific select name doesn&#39;t already exist - as all other options have the same amount assigned to it - it&#39;s just indicating which one was selected.

I&#39;m not sure if that makes sense - but have a look at the code - perhaps this will make it clearer:

    $(&quot;#add_ons select&quot;).change(function() {
			// get current price of the addons
			var order_price_addon = $(&quot;.order_price_addon&quot;).text();
			// get price of the clicked radio button from the rel attribute
			var add = $(this).children(&#39;option&#39;).attr(&#39;label&#39;);
			var name = $(this).attr(&#39;name&#39;);
			var val = $(this).val();
			
			
			if(val == &quot;&quot;) {
				var price = parseInt(order_price_addon) - parseInt(add);
				removeSession(name);
			} else {
				if(isSession(name) == 0) {
					var price = parseInt(order_price_addon) + parseInt(add);
				}	
				setSession(name, val);				
			}
			
			$(&quot;.order_price_addon&quot;).html(price);	
			setSession(&#39;order_price_addon&#39;, price);			
			updateTotal();
	});

so - first of all when the `#add_ons` select menu triggers &quot;change&quot; we get some values from a few elements for calculations.

we get the label attribute of the option from our select which stores the value to be added to the total, name of the select to create session with this name and value to later check which one was selected.

now - we check whether the `val == &quot;&quot;` (which would indicate that None option has been selected) and we deduct the amount from the total as well as remove the session with the select&#39;s name.

After this is where the problem starts - `else` statement.

Else - we want to check whether the `isSession()` function with the name of our selector returns 0 or 1 - if it returns 0  then we add to the total the value stored in the label attribute, but if it returns 1 - that would suggest that session already exists - then we only change the value of this session by recreating it - but the amount isn&#39;t added to it.

Now `isSession` function looks like this:

    function isSession(selector) {
		$.ajax({
			type: &quot;POST&quot;,
			url: &#39;/order.html&#39;,
			data: ({ issession : 1, selector: selector }),
			dataType: &quot;html&quot;,
			success: function(data) {
				return data;
			},
			error: function() {
				alert(&#39;Error occured&#39;);
			}
		});
	}

Now - the problem is - that I don&#39;t know whether using `return` will return the result from the function - as it doesn&#39;t seem to work - however, if I put the &quot;data&quot; in the success: section into the `alert()` - it does seem to return the right value.

Does anyone know how to return the value from the function and then compare it in the next statement?


----------


Thanks guys - I&#39;ve tried it in the following way:

    function isSession(selector) {
		$.ajax({
			type: &quot;POST&quot;,
			url: &#39;/order.html&#39;,
			data: ({ issession : 1, selector: selector }),
			dataType: &quot;html&quot;,
			success: function(data) {
				updateResult(data);
			},
			error: function() {
				alert(&#39;Error occured&#39;);
			}
		});
	}

then the `updateResult()` function:

  

      
    function updateResult(data) {
        result = data;
    }

`result` - is the global variable - which I&#39;m then trying to read:

    $(&quot;#add_ons select&quot;).change(function() {
			// get current price of the addons
			var order_price_addon = $(&quot;.order_price_addon&quot;).text();
			// get price of the clicked radio button from the rel attribute
			var add = $(this).children(&#39;option&#39;).attr(&#39;label&#39;);
			var name = $(this).attr(&#39;name&#39;);
			var val = $(this).val();
			
			
			if(val == &quot;&quot;) {
				var price = parseInt(order_price_addon) - parseInt(add);
				removeSession(name);
			} else {
				isSession(name);
				if(result == 0) {
					var price = parseInt(order_price_addon) + parseInt(add);
				}	
				setSession(name, val);				
			}
			
			$(&quot;.order_price_addon&quot;).html(price);	
			setSession(&#39;order_price_addon&#39;, price);			
			updateTotal();
		});

but for some reason - it doesn&#39;t work - any idea?


jquery - return value using ajax result on success

I&#39;m trying to find information on how to serialize an object to query string format, but all my searches are drowning in results on how to go the other way (string/form/whatever to JSON).

I have

    { one: &#39;first&#39;, two: &#39;second&#39; }

and I want

    ?one=first&amp;two=second

Is there a good way to do this? I don&#39;t mind plugins or whatnots - if the code I find is not a plugin, I&#39;ll probably re-write it to one anyway...

Serialize object to query string in JavaScript/jQuery

I am using a jQuery UI dialog. If it is open, I want to do one thing. If it is closed, I want to do another. 

My question is, how do I detect if a jQuery UI dialog box is open or not?


Detect if a jQuery UI dialog box is open

I am writing a script for customising a configuration file. I want to replace multiple instances of strings within this file, and I tried using PowerShell to do the job.

It works fine for a single replace, but doing multiple replaces is very slow because each time it has to parse the whole file again, and this file is very large. The script looks like this:

    $original_file = &#39;path\filename.abc&#39;
    $destination_file =  &#39;path\filename.abc.new&#39;
    (Get-Content $original_file) | Foreach-Object {
        $_ -replace &#39;something1&#39;, &#39;something1new&#39;
        } | Set-Content $destination_file

I want something like this, but I don&#39;t know how to write it:

    $original_file = &#39;path\filename.abc&#39;
    $destination_file =  &#39;path\filename.abc.new&#39;
    (Get-Content $original_file) | Foreach-Object {
        $_ -replace &#39;something1&#39;, &#39;something1aa&#39;
        $_ -replace &#39;something2&#39;, &#39;something2bb&#39;
        $_ -replace &#39;something3&#39;, &#39;something3cc&#39;
        $_ -replace &#39;something4&#39;, &#39;something4dd&#39;
        $_ -replace &#39;something5&#39;, &#39;something5dsf&#39;
        $_ -replace &#39;something6&#39;, &#39;something6dfsfds&#39;
        } | Set-Content $destination_file


How to replace multiple strings in a file using PowerShell

I have a very large numpy array (containing up to a million elements) like the one below:

    [0,1,6,5,1,2,7,6,2,3,8,7,3,4,9,8,5,6,11,10,6,7,12,11,7,
    8,13,12,8,9,14,13,10,11,16,15,11,12,17,16,12,13,18,17,13,
    14,19,18,15,16,21,20,16,17,22,21,17,18,23,22,18,19,24,23]

and a small dictionary map for replacing some of the elements in the above array

    {4: 0, 9: 5, 14: 10, 19: 15, 20: 0, 21: 1, 22: 2, 23: 3, 24: 0}

I would like to replace some of the elements according to the map above. The numpy array is really large, and only a small subset of the elements (occurring as keys in the dictionary) will be replaced with the corresponding values. What is the fastest way to do this?


Fast replacement of values in a numpy array

I need to replace some characters as follows: `&amp;` ➔ `\&amp;`, `#` ➔ `\#`, ...

I coded as follows, but I guess there should be some better way. Any hints?

    strs = strs.replace(&#39;&amp;&#39;, &#39;\&amp;&#39;)
    strs = strs.replace(&#39;#&#39;, &#39;\#&#39;)
    ...



Best way to replace multiple characters in a string?

Is it possible in C++ to replace part of a string with another string?

Basically, I would like to do this:

    QString string(&quot;hello $name&quot;);
    string.replace(&quot;$name&quot;, &quot;Somename&quot;);

But I would like to use the Standard C++ libraries.


Replace part of a string with another string

I&#39;m trying to do a find and replace over many files within an Eclipse project, but I can&#39;t seem to find a way to do it. Googling showed me that there are plug-ins that can accomplish this, but is there any built-in functionality in Eclipse? (It seems to be a pretty basic task; it&#39;s surprising me that I can&#39;t find a way to do it.)

Content Type	Original Author	Original Content on Stackoverflow
Question	Alex	View Question on Stackoverflow
Solution 1 - Javascript	Josiah	View Answer on Stackoverflow
Solution 2 - Javascript	Greg Shackles	View Answer on Stackoverflow
Solution 3 - Javascript	redexp	View Answer on Stackoverflow
Solution 4 - Javascript	kennebec	View Answer on Stackoverflow

Remove all multiple spaces in Javascript and replace with single space

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

Solution 3 - Javascript

Solution 4 - Javascript

How to change backends in matplotlib / Python

Android, Detect when other apps are launched

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