Replace multiple whitespaces with single whitespace in JavaScript string - javascript

I have strings with extra whitespace characters. Each time there's more than one whitespace, I'd like it be only one. How can I do this using JavaScript?


Something like this:
var s = " a b c ";
console.log(
s.replace(/\s+/g, ' ')
)


You can augment String to implement these behaviors as methods, as in:
String.prototype.killWhiteSpace = function() {
return this.replace(/\s/g, '');
};
String.prototype.reduceWhiteSpace = function() {
return this.replace(/\s+/g, ' ');
};
This now enables you to use the following elegant forms to produce the strings you want:
"Get rid of my whitespaces.".killWhiteSpace();
"Get rid of my extra whitespaces".reduceWhiteSpace();


Here's a non-regex solution (just for fun):
var s = ' a b word word. word, wordword word ';
// with ES5:
s = s.split(' ').filter(function(n){ return n != '' }).join(' ');
console.log(s); // "a b word word. word, wordword word"
// or ES2015:
s = s.split(' ').filter(n => n).join(' ');
console.log(s); // "a b word word. word, wordword word"
Can even substitute filter(n => n) with .filter(String)
It splits the string by whitespaces, remove them all empty array items from the array (the ones which were more than a single space), and joins all the words again into a string, with a single whitespace in between them.


using a regular expression with the replace function does the trick:
string.replace(/\s/g, "")


I presume you're looking to strip spaces from the beginning and/or end of the string (rather than removing all spaces?
If that's the case, you'll need a regex like this:
mystring = mystring.replace(/(^\s+|\s+$)/g,' ');
This will remove all spaces from the beginning or end of the string. If you only want to trim spaces from the end, then the regex would look like this instead:
mystring = mystring.replace(/\s+$/g,' ');
Hope that helps.


jQuery.trim() works well.
http://api.jquery.com/jQuery.trim/


I know I should not necromancy on a subject, but given the details of the question, I usually expand it to mean:
I want to replace multiple occurences of whitespace inside the string with a single space
...and... I do not want whitespaces in the beginnin or end of the string (trim)
For this, I use code like this (the parenthesis on the first regexp are there just in order to make the code a bit more readable ... regexps can be a pain unless you are familiar with them):
s = s.replace(/^(\s*)|(\s*)$/g, '').replace(/\s+/g, ' ');
The reason this works is that the methods on String-object return a string object on which you can invoke another method (just like jQuery & some other libraries). Much more compact way to code if you want to execute multiple methods on a single object in succession.


var x = " Test Test Test ".split(" ").join("");
alert(x);


Try this.
var string = " string 1";
string = string.trim().replace(/\s+/g, ' ');
the result will be
string 1
What happened here is that it will trim the outside spaces first using trim() then trim the inside spaces using .replace(/\s+/g, ' ').


How about this one?
"my test string \t\t with crazy stuff is cool ".replace(/\s{2,9999}|\t/g, ' ')
outputs "my test string with crazy stuff is cool "
This one gets rid of any tabs as well


If you want to restrict user to give blank space in the name just create a if statement and give the condition. like I did:
$j('#fragment_key').bind({
keypress: function(e){
var key = e.keyCode;
var character = String.fromCharCode(key);
if(character.match( /[' ']/)) {
alert("Blank space is not allowed in the Name");
return false;
}
}
});
create a JQuery function .
this is key press event.
Initialize a variable.
Give condition to match the character
show a alert message for your matched condition.

Related

js compare between variable and div text

I'm trying to compare value of text inside div (This is a sentence.) and text defined in js variable:
function isSame(){
s="This is a sentence."
var text1 = $('#right').text();
var t1 = text1.replace(/ /g,'').replace(/ /g, '').replace(/\<br\s*[\/]?>/gi, '').replace('\t','');
var s1 = s.replace(/ /g,'').replace(/ /g, '').replace(/\<br\s*[\/]?>/gi, '').replace('\t','');
console.log(s1+" VS "+ t1);
if (t1 == s1){
console.log("Same");
} else {
console.log("Not same...");
}
}
All the .replace are because on console I had extra tabs in div (which has style in it) I had extra spaces. Console log shows:
Thisisasentence. VS
Thisisasentence.
Not same...
What is it I'm missing?

Instead of this entire regular expression, have you tried using the trim() method?
As stated in the documentation for String.prototype.trim(), in MDN:
The trim() method removes whitespace from both ends of a string. Whitespace in this context is all the whitespace characters (space, tab, no-break space, etc.) and all the line terminator characters (LF, CR, etc.).
I believe your code should then be reduced to:
function isSame() {
var s = "This is a sentence.";
var text1 = $('#right').text();
console.log(s1 + " VS " + t1);
if (text1.trim() === s1) {
console.log("Same");
} else {
console.log("Not the same...");
}
}
And the comparison would work as expected.
Update:
As already mentioned in further answers by Ysharp and Rob Brander, you could increment your regular expression by expanding it to other match new lines and carriage return elements. That would change your current regex by adding a \s+ matcher to it, resulting in:
replace(/\s+/g, '')

Your regular expressions look like they're trying to replace any whitespace characters. I would suggest using \s as part of your regular expression, because that looks for all permutations of whitespace.
Your two strings are not equal because there is a newline before and after the phrase. You could try replacing just the new lines with .replace('\n', '')

You tried to get rid of whitespace using
replace(/ /g, '')
but as others pointed out, this is not sufficient to get rid of carriage returns and/or newlines.
Try this instead:
replace(/\s+/g, '')
which will take care of stripping out all of the '\t', '\n', etc, everywhere in the strings it is applied to.
'HTH,

JavaScript: How can I remove any words containing (or directly preceding) capital letters, numbers, or commas, from a string?

I'm trying to write the code so it removes the "bad" words from the string (the text).
The word is "bad" if it has comma or any special sign thereafter. The word is not "bad" if it contains only a to z (small letters).
So, the result I'm trying to achieve is:
<script>
String.prototype.azwords = function() {
return this.replace(/[^a-z]+/g, "0");
}
var res = "good Remove remove1 remove, ### rem0ve? RemoVE gooood remove.".azwords();//should be "good gooood"
//Remove has a capital letter
//remove1 has 1
//remove, has comma
//### has three #
//rem0ve? has 0 and ?
//RemoVE has R and V and E
//remove. has .
alert(res);//should alert "good gooood"
</script>

Try this:
return this.replace(/(^|\s+)[a-z]*[^a-z\s]\S*(?!\S)/g, "");
It tries to match a word (that is surrounded by whitespaces / string ends) and contains any (non-whitespace) character but at least one that is not a-z. However, this is quite complicated and unmaintainable. Maybe you should try a more functional approach:
return this.split(/\s+/).filter(function(word) {
return word && !/[^a-z]/.test(word);
}).join(" ");

okay, first off you probably want to use the word boundary escape \b in your regex. Also, it's a bit tricky if you match the bad words, because a bad word might contain lower case chars, so your current regex will exclude anything which does have lowecase letters.
I'd be tempted to pick out the good words and put them in a new string. It's a much easier regex.
/\b[a-z]+\b/g
NB: I'm not totally sure that it'll work for the first and last words in the string so you might need to account for that as well. http://www.regextester.com/ is exceptionally useful.
EDIT: as you want punctiation after the word to be 'bad', this will actually do what I was suggesting
(^|\s)[a-z]+(\s|$)

Firstly I wouldn't recommend changing the prototype of String (or of any native object) if you can avoid because you leave yourself open to conflicts with other code that might define the same property in different ways. Much better to put custom methods like this on a namespaced object, though I'm sure some will disagree.
Second, is there any need to use RegEx completely? (Genuine question; not trying to be facetious.)
Here is an example of the function with plain old JS using a little bit of RegEx here and there. Easier to comment, debug, and reuse.
Here is the code:
var azwords = function(str) {
var arr = str.split(/\s+/),
len = arr.length,
i = 0,
res = "";
for (i; i < len; i += 1) {
if (!(arr[i].match(/[^a-z]/))) {
res += (!res) ? arr[i] : " " + arr[i];
}
}
return res;
}
var res = "good Remove remove1 remove, ### rem0ve? RemoVE gooood remove."; //should be "good gooood"
//Remove has a capital letter
//remove1 has 1
//remove, has comma
//### has three #
//rem0ve? has 0 and ?
//RemoVE has R and V and E
//remove. has .
alert(azwords(res));//should alert "good gooood";

Try this one:
var res = "good Remove remove1 remove, ### rem0ve? RemoVE gooood remove.";
var new_one = res.replace(/\s*\w*[#A-Z0-9,.?\\xA1-\\xFF]\w*/g,'');
//Output `good gooood`
Description:
\s* # zero-or-more spaces
\w* # zero-or-more alphanumeric characters
[#A-Z0-9,.?\\xA1-\\xFF] # matches any list of characters
\w* # zero-or-more alphanumeric characters
/g - global (run over all string)

This will find all the words you want /^[a-z]+\s|\s[a-z]+$|\s[a-z]+\s/g so you could use match.
this.match(/^[a-z]+\s|\s[a-z]+$|\s[a-z]+\s/g).join(" "); should return the list of valid words.
Note that this took some time as a JSFiddle so it maybe more efficient to split and iterate your list.

How can I get a substring located between 2 quotes?

I have a string that looks like this: "the word you need is 'hello' ".
What's the best way to put 'hello' (but without the quotes) into a javascript variable? I imagine that the way to do this is with regex (which I know very little about) ?
Any help appreciated!

Use match():
> var s = "the word you need is 'hello' ";
> s.match(/'([^']+)'/)[1];
"hello"
This will match a starting ', followed by anything except ', and then the closing ', storing everything in between in the first captured group.

http://jsfiddle.net/Bbh6P/
var mystring = "the word you need is 'hello'"
var matches = mystring.match(/\'(.*?)\'/); //returns array
​alert(matches[1]);​

If you want to avoid regular expressions then you can use .split("'") to split the string at single quotes , then use jquery.map() to return just the odd indexed substrings, ie. an array of all single-quoted substrings.
var str = "the word you need is 'hello'";
var singleQuoted = $.map(str.split("'"), function(substr, i) {
return (i % 2) ? substr : null;
});
DEMO
CAUTION
This and other methods will get it wrong if one or more apostrophes (same as single quote) appear in the original string.

Searching for a last word in JavaScript

I am doing some logic for the last word that is on the sentence. Words are separated by either space or with a '-' character.
What is easiest way to get it?
Edit
I could do it by traversing backwards from the end of the sentence, but I would like to find better way

Try splitting on a regex that matches spaces or hyphens and taking the last element:
var lastWord = function(o) {
return (""+o).replace(/[\s-]+$/,'').split(/[\s-]/).pop();
};
lastWord('This is a test.'); // => 'test.'
lastWord('Here is something to-do.'); // => 'do.'
As #alex points out, it's worth trimming any trailing whitespace or hyphens. Ensuring the argument is a string is a good idea too.

Using a regex:
/.*[\s-](\S+)/.exec(str)[1];
that also ignores white-space at the end

Have you tried the lastIndexOf function http://www.w3schools.com/jsref/jsref_lastIndexOf.asp
Or Split function http://www.w3schools.com/jsref/jsref_split.asp

Here is a similar discussion have a look

You can try something like this...
<script type="text/javascript">
var txt = "This is the sample sentence";
spl = txt.split(" ");
for(i = 0; i < spl.length; i++){
document.write("<br /> Element " + i + " = " + spl[i]);
}
</script>

Well, using Split Function
string lastWord = input.Split(' ').Last();
or
string[] parts = input.Split(' ');
string lastWord = parts[parts.Length - 1];
While this would work for this string, it might not work for a slightly different string, so either you'll have to figure out how to change the code accordingly, or post all the rules.
string input = ".... ,API";
here, the comma would be part of the "word".
Also, if the first method of obtaining the word is correct, ie. everything after the last space, and your string adheres to the following rules:
Will always contain at least one space
Does not end with one or more space (in case of this you can trim it)
then you can use this code that will allocate fewer objects on the heap for GC to worry about later:
string lastWord = input.Substring(input.LastIndexOf(' ') + 1);
I hope its help

remove unwanted commas in JavaScript

I want to remove all unnecessary commas from the start/end of the string.
eg; google, yahoo,, , should become google, yahoo.
If possible ,google,, , yahoo,, , should become google,yahoo.
I've tried the below code as a starting point, but it seems to be not working as desired.
trimCommas = function(s) {
s = s.replace(/,*$/, "");
s = s.replace(/^\,*/, "");
return s;
}

In your example you also want to trim the commas if there's spaces between them at the start or at the end, use something like this:
str.replace(/^[,\s]+|[,\s]+$/g, '').replace(/,[,\s]*,/g, ',');
Note the use of the 'g' modifier for global replace.

You need this:
s = s.replace(/[,\s]{2,}/,""); //Removes double or more commas / spaces
s = s.replace(/^,*/,""); //Removes all commas from the beginning
s = s.replace(/,*$/,""); //Removes all commas from the end
EDIT: Made all the changes - should work now.

My take:
var cleanStr = str.replace(/^[\s,]+/,"")
.replace(/[\s,]+$/,"")
.replace(/\s*,+\s*(,+\s*)*/g,",")
This one will work with opera, internet explorer, whatever
Actually tested this last one, and it works!

What you need to do is replace all groups of "space and comma" with a single comma and then remove commas from the start and end:
trimCommas = function(str) {
str = str.replace(/[,\s]*,[,\s]*/g, ",");
str = str.replace(/^,/, "");
str = str.replace(/,$/, "");
return str;
}
The first one replaces every sequence of white space and commas with a single comma, provided there's at least one comma in there. This handles the edge case left in the comments for "Internet Explorer".
The second and third get rid of the comma at the start and end of string where necessary.
You can also add (to the end):
str = str.replace(/[\s]+/, " ");
to collapse multi-spaces down to one space and
str = str.replace(/,/g, ", ");
if you want them to be formatted nicely (space after each comma).
A more generalized solution would be to pass parameters to indicate behaviour:
Passing true for collapse will collapse the spaces within a section (a section being defined as the characters between commas).
Passing true for addSpace will use ", " to separate sections rather than just "," on its own.
That code follows. It may not be necessary for your particular case but it might be better for others in terms of code re-use.
trimCommas = function(str,collapse,addspace) {
str = str.replace(/[,\s]*,[,\s]*/g, ",").replace(/^,/, "").replace(/,$/, "");
if (collapse) {
str = str.replace(/[\s]+/, " ");
}
if (addspace) {
str = str.replace(/,/g, ", ");
}
return str;
}

First ping on Google for "Javascript Trim": http://www.somacon.com/p355.php. You seem to have implemented this using commas, and I don't see why it would be a problem (though you escaped in the second one and not in the first).

Not quite as sophisticated, but simple with:
',google,, , yahoo,, ,'.replace(/\s/g, '').replace(/,+/g, ',');

You should be able to use only one replace call:
/^( *, *)+|(, *(?=,|$))+/g
Test:
'google, yahoo,, ,'.replace(/^( *, *)+|(, *(?=,|$))+/g, '');
"google, yahoo"
',google,, , yahoo,, ,'.replace(/^( *, *)+|(, *(?=,|$))+/g, '');
"google, yahoo"
Breakdown:
/
^( *, *)+ # Match start of string followed by zero or more spaces
# followed by , followed by zero or more spaces.
# Repeat one or more times
| # regex or
(, *(?=,|$))+ # Match , followed by zero or more spaces which have a comma
# after it or EOL. Repeat one or more times
/g # `g` modifier will run on until there is no more matches
(?=...) is a look ahead will will not move the position of the match but only verify that a the characters are after the match. In our case we look for , or EOL

match() is much better tool for this than replace()
str = " aa, bb,, cc , dd,,,";
newStr = str.match(/[^\s,]+/g).join(",")
alert("[" + newStr + "]")

When you want to replace ",," ",,,", ",,,," and ",,,,," below code will be removed by ",".
var abc = new String("46590,26.91667,75.81667,,,45346,27.18333,78.01667,,,45630,12.97194,77.59369,,,47413,19.07283,72.88261,,,45981,13.08784,80.27847,,");
var pqr= abc.replace(/,,/g,',').replace(/,,/g, ',');
alert(pqr);

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