I cannot find a good way to split a string using a separator string but leave the separator as the prefix of each element of the resulting array:
from
var s = 'blah0__blah1__blah2';
I need to get
['blah0', '__blah1', '__blah2']
the closest thing that I could get was
s.split(/(__)/);
which returns
['blah0', '__', 'blah1', '__', 'blah2']
but this I would need to traverse to merge the underscores.
Is there a better way?
EDIT:
here is my best effort so far:
'blah__blah1__blah2'.split(/(__[^_]+)/)
// => ["blah", "__blah1", "", "__blah2", ""]
still, there are empty strings in the output...
How about this:
var s = 'blah0__blah__blah'
var s_split = s.match(/(__)?(.(?!__))+./g)
console.log(s_split)
I'm pretty sure it's much more costly (time and memory wise) than simply reiterating and joining after a regular split.
If you replace __ with your separator it should work fine for most cases.
A two-step process.
var s = 'blah0__blah1__blah2';
var blahs = s.split('__');
var scoreBlahs = blahs.map(preScore);
alert(scoreBlahs);
function preScore(b) {
var x;
var result = x.concat('__',b);
return result;
}
'blah0__blah1__blah2'.match(/^[^_]+|_+[^_]+/g);
["blah0", "__blah1", "__blah2"]
Seems to give you what you want. Though It may vary, if your input isn't exactly as you show it.
Just prepend the seperator after you seperate the string
var value = "a,b,c";
var splitter = value.split(",");
for(var i = 0; i < splitter.length; i++) {
alert("," + splitter[i]);
}
Since you know the separator - just add it again later on:
var s = 'blah0__blah1__blah2';
var sep = '__';
var arr = s.split(sep);
for (var i = 1; i < arr.length; i++) {
arr[i] = sep + arr[i];
}
console.log(arr);
You could insert a secondary separator, and split on that, leaving the original intact.
var s = 'blah0__blah1__blah2';
s = s.replace('_', '_$');
s.split('$');
Related
wordsArray = ['guy', 'like', 'sweet', 'potatoes']; //so on and so forth
string = "I am a **NOUN** and I **VERB** **ADJECTIVE** **NOUN**.";
DELIMITER = "**";
for (var i = 0; i < wordsArray.length; i++)
{
string.replace(DELIMITER, wordsArray[i]);
}
Hi, this is a simplified version of my code. I'm creating a mad lib, and the length of wordsArray will always be equal to the number of fill in the blanks. The problem with my current code is that in the for loop, it will replace every **. The thing is, I want to replace the entire thing, like **NOUN**, not just **. But since whatever is in between ** ** won't always be the same, string.replace() won't exactly work. Can Anyone suggest me an edit that could replace all the part of speeches but still eventually return string as a, well, block of proper text?
You can do it using string.match by catching all those **<STRINGS>** first:
var wordsArray = ['guy', 'like', 'sweet', 'potatoes'];
var string = "I am a **NOUN** and I **VERB-** **ADJECTIVE** **NOUN**.";
var DELIMITER = "**";
var newString = string; // copy the string
var stringArray = string.match(/(\*\*[A-Za-z-]+\*\*)/g); // array of all **<STRINGS>**
for (var i = 0; i < wordsArray.length; i++) {
newString = newString.replace(stringArray[i], wordsArray[i]);
}
console.log(newString);
You can bind your array to the replacer and call replace on your string once, I think it is much simpler:
"I am a **NOUN** and I **VERB** **ADJECTIVE** **NOUN**.".replace(/(\*\*\w+\*\*)/gi,(function(){
this._currentIndex = this._currentIndex || 0;
return this[this._currentIndex++];
}).bind(['guy', 'like', 'sweet', 'potatoes']));
//"I am a guy and I like sweet potatoes."
Using reduce:
const string = "I am a **NOUN** and I **VERB** **ADJECTIVE** **NOUN**.";
const newString = ['guy', 'like', 'sweet', 'potatoes'].reduce(
(theString, replacement) => theString.replace(/\*{2}\w+\*{2}/, replacement),
string
)
javascript, what is the best way to replace following two scenario.
It is possible to use replace and add regex to do this, if yes, how?
I want to convert "aaa.bbb.ccc" TO "aaa.bbb.*"
I want to convert "aaa.bbb.ccc.ddd.eee" TO "aaa.bbb.*.ddd.*"
var map = 'qwertyuiopasdfghjklzxcvbnm'.split('');
var rand = function(){
var len = map.length,
arr = [],
i;
for (i = 0; i < 3; i++){
arr.push(map[Math.floor(Math.random()*len)]);
}
return arr.join('');
};
var randStr = [rand(), rand()];
/* ASSUME above code is how you get random string */
var string = 'aaa.bbb.' + randStr[0] + '.ddd.' + randStr[1];
// use new RegExp() to parse string as regular expression
var regexp = new RegExp(randStr[0] + '|' + randStr[1], 'gi');
console.log(string.replace(regexp, '*'));
Read more about new RegExp() here (easy one), here (detailed one) and here (working example).
You should be able to apply this concept in your code now.
I have a string which I need to separate correctly:
self.view.frame.size.height = 44
I need to get only view, frame, size, and height. And I need to do it with a regular expression.
So far I've tried a lot of variants, none of them are even close to what I want to get. And my code now looks like this:
var testString = 'self.view.frame.size.height = 44'
var re = new RegExp('\\.(.*)\\.', "g")
var array = re.exec(testString);
console.log('Array length is ' + array.length)
for (var i = 0; i < array.length; i++) {
console.log('<' + array[i] + ">");
}
And it doesn't work at all:
Array length is 2
<.view.frame.size.>
<view.frame.size>
I'm new at Javascript, so maybe I want the impossible, let me know.
Thanks.
In Javascript, executing a regexp with the g modifier doesn't return all the matches at once. You have to execute it repeatedly on the same input string, and each one returns the next match.
You also need to change the regexp so it only returns one word at a time. .* is greedy, so it returns the longest possible match, so it was returning all the words between the first and last .. [^.]* will match a sequence of non-dot characters, so it will just return one word. You can't include the second . in the regexp, because that will interfere with the repetition -- each repetition starts searching after the end of the previous match, and there's no beginning . after the ending . of the word. Also, there's no . after height, so the last word won't match it.
EDIT: I've changed the regexp to use \w* instead of [^.]*, because it was grabbing the whole height = 44 string instead of just height.
var testString = 'self.view.frame.size.height = 44';
var re = /\.(\w*)/g;
var array = [];
var result;
while (result = re.exec(testString)) {
array.push(result[1]);
}
console.log('Array length is ' + array.length)
for (var i = 0; i < array.length; i++) {
console.log('<' + array[i] + ">");
}
If you're sure that your data will be always in the same format you can use this:
function parse (string) {
return string.split(" = ").shift().split(".").splice(1);
}
In your context, split is a MUCH better option:
var str = "self.view.frame.size.height = 44";
var bits1 = str.split(" ")[0];
var bits2 = bits1.split(".");
bits2.shift(); // get rid of the unwanted self
console.log(bits2);
I understand the .split() function quite well. But what I can seem to figure out is how to split in certain places but not in others. Sounds confusing? Well I mean for example, lets say I use .split(",") on the following string:
div:(li,div),div
Is it possible to split it so that only the commas ouside of the parentheses get split.
So the string above with the split method should return:
['div:(li,div)', 'div']
Of course at the moment it is also splitting the first comma inside of the parentheses, returning:
['div:(li', 'div)', 'div']
Is there some way to make this work like I desire?
If your expected strings are not going to become more complicated than this, you don't have to worry about writing code to parse them. Regex will work just fine.
http://jsfiddle.net/dC5HN/1/
var str = "div:(li,div),div:(li,div),div";
var parts = str.split(/,(?=(?:[^\)]|\([^\)]*\))*$)/g);
console.log(parts);
outputs:
["div:(li,div)", "div:(li,div)", "div"]
REGEX is not built for this sort of thing, which is essentially parsing.
When faced with this sort of situation previously I've first temporarily replaced the parenthesised parts with a placeholder, then split, then replaced the placeholders with the original parenthised parts.
A bit hacky, but it works:
var str = 'div:(li,div),div',
repls = [];
//first strip out parenthesised parts and store in array
str = str.replace(/\([^\)]*\)/g, function($0) {
repls.push($0);
return '*repl'+(repls.length - 1)+'*';
});
//with the parenthisised parts removed, split the string then iteratively
//reinstate the removed parenthisised parts
var pieces = str.split(',').map(function(val, index) {
return val.replace(/\*repl(\d+)\*/, function($0, $1) {
return repls[$1];
});
});
//test
console.log(pieces); //["div:(li,div)","div"]
This function will split whatever you specify in splitChar, but ignore that value if inside parenthesis:
function customSplit(stringToSplit, splitChar){
var arr = new Array();
var isParenOpen = 0
var curChar;
var curString = "";
for (var i = 0; i < stringToSplit.length; i++) {
curChar = stringToSplit.substr(i, 1);
switch(curChar) {
case "(":
isParenOpen++;
break;
case ")":
if(isParenOpen > 0) isParenOpen--;
break;
case splitChar:
if (isParenOpen < 1) {
arr.push(curString);
curString = "";
continue;
}
}
curString += curChar;
}
if (curString.length > 0) {
arr.push(curString);
}
return arr;
}
I have a javascript array which holds strings of last names.
I need to loop this array and separate out the last names which match a given string.
var names = ['woods','smith','smike'];
var test = 'smi';
var c = 0;
var result = new Array();
for(var i = 0; i < names.length; i++)
{
if(names[i].match(test))// need regular expression for this
result[c++] = names[i];
}
return result;
name should match the test string even if the test lies within the name. so... mik should match 'Mike' and 'Smike' also.
Any help is really appreciated!
You can create a regex from a string:
var nameRe = new RegExp("mik", "i");
if(names[i].match(nameRe))
{
result.push(names[i]);
}
Make sure to escape regex meta-characters though - if your string may contain them. For example ^, $ may result in a miss-match, and *, ? ) and more may result in an invalid regex.
More info: regular-expressions.info/javascript
You can do this without regex:
if (names[i].toLowerCase().indexOf(test.toLowerCase()) >= 0)
// ...
Javascript string .search is what you're looking for.. You don't even need regex although search supports that too.
var names = ['woods','smith','smike'];
var test = 'smi';
var c = 0;
var result = new Array();
for(var i = 0; i < names.length; i++)
{
if(names[i].toLowerCase().search(test))// need regular expression for this
result.push(names[i]);
}
return result;
You can do this with one regex.
var r = new RegExp(names.join('|'), "igm");
'woods smith'.match(r);
You don't need regex for this, so I'd recommend using string manipulation instead. It's almost (almost!) always better to use string functions instead of regex when you can: They're usually faster, and it's harder to make a mistake.
for(var i = 0; i < names.length; i++)
{
if(names[i].indexOf(test) > -1)
//match, do something with names[i]...
}