How can I test if a RegEx matches a string exactly?
var r = /a/;
r.test("a"); // returns true
r.test("ba"); // returns true
testExact(r, "ba"); // should return false
testExact(r, "a"); // should return true
Either modify the pattern beforehand so that it only matches the entire string:
var r = /^a$/
or check afterward whether the pattern matched the whole string:
function matchExact(r, str) {
var match = str.match(r);
return match && str === match[0];
}
Write your regex differently:
var r = /^a$/;
r.test('a'); // true
r.test('ba'); // false
If you do not use any placeholders (as the "exactly" seems to imply), how about string comparison instead?
If you do use placeholders, ^ and $ match the beginning and the end of a string, respectively.
In case anyone receives an error like
Syntax Error: Invalid regular expression
by using the .match() function. You could always go back to the roots:
!!note this code is for matchin an exact string, if you want to search for an exact phrase in a string, you should filter it before hand
console.log("Exact data found: ", hasExactString("?hello", "?hello"))
console.log("Exact data found: ", hasExactString("?hello", "?helloBye"))
function hasExactString(data, searchTerm) {
console.log("search for ", searchTerm, " in ", data);
data = data.toLowerCase(); //if search term should be case insensitive
const searchExpressionLength = searchTerm.length;
const dataInputLength = data.length;
if (dataInputLength != searchExpressionLength) {
return false;
}
else {
//search letter by letter -back to the roots
for (var i = 0; i < searchExpressionLength; i++) {
if (data[i] != searchTerm[i]) {
return false;
}
}
return true;
}
}
...13 years late, but nonetheless^^
var data = {"values": [
{"name":0,"value":0.12791263050161572},
{"name":1,"value":0.13158780927382124}
]};
//JSON to string conversion
var a = JSON.stringify(data);
// replace all name with "x"- global matching
var t = a.replace(/name/g,"x");
// replace exactly the value rather than all values
var d = t.replace(/"value"/g, '"y"');
// String to JSON conversion
var data = JSON.parse(d);
Here's what is (IMO) by far the best solution in one line, per modern javascript standards:
const str1 = 'abc';
const str2 = 'abc';
return (str1 === str2); // true
const str1 = 'abcd';
const str2 = 'abc';
return (str1 === str2); // false
const str1 = 'abc';
const str2 = 'abcd';
return (str1 === str2); // false
I'm trying to match some words in a string. But I don't have a predefined number of words I need to find.
For example I search for Ubuntu 18 10 in ubuntu-18.10-desktop-amd64.iso.torrent would return true.
Or I could search for centos 7 in CentOS-7-x86_64-LiveGNOME-1804.torrent would also return true.
I don't need to check if it's lowercase or not.
What I tried :
$.get('interdit', function(data) {
var lines = data.split("\n");
$.each(lines, function(n, data_interdit) {
var url_check = $('textarea#url').val()
var split_forbidden = data_interdit.split(/[\s|,|_|.|-|:]+/);
var exist = 0;
$.each(split_forbidden, function(n, data) {
var n = url_check.search("^("+ data +")");
if(n != -1){
exist = 1
}else{
exist = 0
}
console.log('Forbidden: '+ data + ' Result: ' + n);
})
if(exist == 1){
console.log('found')
}
});
});
Sample data of the file interdit :
CentOS.7
Ubuntu-18
You want to look for existing words within the input string without the order being taken into account. You need to use positive lookaheads for this:
var search = 'Ubuntu 18 10';
var str = 'ubuntu-18.10-desktop-amd64.iso.torrent';
var re = new RegExp('^(?=.*' + search.split(/[\s,_.:-]+/).join(')(?=.*') + ')', 'i')
console.log(re.test(str));
This produces a regex as the following (with i flag set):
^(?=.*Ubuntu)(?=.*18)(?=.*10)
RegEx Array
Update
"The code give me an error jsbin.com/pecoleweyi/2/edit?js,console"
Although the question did not include unlikely input such as: *centos 7*, add the following line to escape the special characters that occur in input:
var esc = word.replace(/[.*+?^${}()|[\]\\]/gi, '\\$&');
and change the next line:
var sub = esc.replace(/\s/gi, '.');
The demo below will:
accept a string (str) to search and an array of strings (tgt) to find within the string,
.map() the array (tgt) which will run a function on each string (word)
escape any special characters:
var esc = word.replace(/[.*+?^${}()|[\]\\]/gi, '\\$&');
replace any spaces (/\s/g) with a dot (.):
var sub = esc.replace(/\s/g, '.');
then makes a RegExp() Object so a variable can be inserted in the pattern via template literal interpolation (say that ten times fast):
var rgx = new RegExp(`${sub}`, `gim`);
uses .test() to get a boolean: found = true / not found = false
var bool = rgx.test(str);
create an Object to assign the search string: word as a property and the boolean: bool as it's value.
var obj = {
[word]: bool
};
returns an array of objects:
[{"centos 7":true},{"Ubuntu 18 10":true}]
Demo
var str = `ubuntu-18.10-desktop-amd64.iso.torrent
CentOS-7-x86_64-LiveGNOME-1804.torrent`;
var tgt = [`centos 7`, `Ubuntu 18 10`, `corn flakes`, `gnome`, `Red Hat`, `*centos 7*`];
function rgxArray(str, tgt) {
var res = tgt.map(function(word) {
var esc = word.replace(/[.*+?^${}()|[\]\\]/gi, '\\$&');
var sub = esc.replace(/\s/gi, '.');
var rgx = new RegExp(`${sub}`, `gi`);
var bool = rgx.test(str);
var obj = {
[word]: bool
};
return obj;
});
return res;
}
console.log(JSON.stringify(rgxArray(str, tgt)));
how would you go about outputting the found output, including the rest of the string its apart of? The array is just full of strings. Thanks
var searchingfor = document.getElementById('searchfield').value;
var searchingforinlowerCase = searchingfor.toLowerCase();
var searchDiv = document.getElementById('searchDiv');
var convertarraytoString = appointmentArr.toString();
var arraytolowerCase = convertarraytoString.toLowerCase();
var splitarrayString = arraytolowerCase.split(',')
if(search(searchingforinlowerCase, splitarrayString) == true) {
alert( searchingforinlowerCase + ' was found at index' + searchLocation(searchingforinlowerCase,splitarrayString) + ' Amount of times found = ' +searchCount(searchingforinlowerCase,splitarrayString));
function search(target, arrayToSearchIn) {
var i;
for (i=0; i<arrayToSearchIn.length; i++)
{ if (arrayToSearchIn[i] == target && target !=="")
return true;
}
Try this
if(search(searchingforinlowerCase, appointmentArr) == true) {
alert( searchingforinlowerCase + ' was found at index' + searchLocation(searchingforinlowerCase,splitarrayString) + ' Amount of times found = ' +searchCount(searchingforinlowerCase,splitarrayString));
function search(target, arrayToSearchIn) {
var i;
for (i=0; i<arrayToSearchIn.length; i++)
{ if (arrayToSearchIn[i].indexOf(target >= 0))
return true;
}
return false;
}
This code will help you find that a match is present. You can update code to display full text where match was found. Original posted code was comparing entire string rather than partial match.
You can do like this
var test = 'Hello World';
if (test.indexOf('Wor') >= 0)
{
/* found substring Wor */
}
In your posted code you are converting Array to string and then again converting it back to Array using split(). That is unnecessary. search can be invoked as
search(searchingforinlowerCase, appointmentArr);
Try utilizing Array.prototype.filter() , String.prototype.indexOf()
// input string
var str = "america";
// array of strings
var arr = ["First Name: John, Location:'america'", "First Name: Jane, Location:'antarctica'"];
// filter array of strings
var res = arr.filter(function(value) {
// if `str` found in `value` , return string from `arr`
return value.toLowerCase().indexOf(str.toLowerCase()) !== -1
});
// do stuff with returned single , or strings from `arr`
console.log(res, res[0])
The following will look for a word in an array of strings and return all the strings that match the word. Is this something you are looking for?
var a = ["one word", "two sentence", "three paragraph", "four page", "five chapter", "six section", "seven book", "one, two word", "two,two sentence", "three, two paragraph", "four, two page", "five, two chapter",];
function search(needle, haystack){
var results = [];
haystack.forEach(function(str){
if(str.indexOf(needle) > -1){
results.push(str);
}
});
return results.length ? results : '';
};
var b = search("word", a);
console.log(b);
Here's the fiddle to try.
var string = "Let's say the user inputs hello world inputs inputs inputs";
My input to get the whole word is "put".
My expected word is "inputs"
Can anyone share your solution?
Thanks in advance
One way to do what you're asking is to split the input string into tokens, then check each one to see if it contains the desired substring. To eliminate duplicates, store the words in an object and only put a word into the result list if you're seeing it for the first time.
function findUniqueWordsWithSubstring(text, sub) {
var words = text.split(' '),
resultHash = {},
result = [];
for (var i = 0; i < words.length; ++i) {
var word = words[i];
if (word.indexOf(sub) == -1) {
continue;
}
if (resultHash[word] === undefined) {
resultHash[word] = true;
result.push(word);
}
}
return result;
}
var input = 'put some putty on the computer output',
words = findUniqueWordsWithSubstring(input, 'put');
alert(words.join(', '));
A RegEx and filter to remove duplicates;
var string = "I put putty on the computer. putty, PUT do I"
var uniques = {};
var result = (string.match(/\b\w*put\w*\b/ig) || []).filter(function(item) {
item = item.toLowerCase();
return uniques[item] ? false : (uniques[item] = true);
});
document.write( result.join(", ") );
// put, putty, computer
I have a string:
var string = "aaaaaa<br />† bbbb<br />‡ cccc"
And I would like to split this string with the delimiter <br /> followed by a special character.
To do that, I am using this:
string.split(/<br \/>&#?[a-zA-Z0-9]+;/g);
I am getting what I need, except that I am losing the delimiter.
Here is the example: http://jsfiddle.net/JwrZ6/1/
How can I keep the delimiter?
I was having similar but slight different problem. Anyway, here are examples of three different scenarios for where to keep the deliminator.
"1、2、3".split("、") == ["1", "2", "3"]
"1、2、3".split(/(、)/g) == ["1", "、", "2", "、", "3"]
"1、2、3".split(/(?=、)/g) == ["1", "、2", "、3"]
"1、2、3".split(/(?!、)/g) == ["1、", "2、", "3"]
"1、2、3".split(/(.*?、)/g) == ["", "1、", "", "2、", "3"]
Warning: The fourth will only work to split single characters. ConnorsFan presents an alternative:
// Split a path, but keep the slashes that follow directories
var str = 'Animation/rawr/javascript.js';
var tokens = str.match(/[^\/]+\/?|\//g);
Use (positive) lookahead so that the regular expression asserts that the special character exists, but does not actually match it:
string.split(/<br \/>(?=&#?[a-zA-Z0-9]+;)/g);
See it in action:
var string = "aaaaaa<br />† bbbb<br />‡ cccc";
console.log(string.split(/<br \/>(?=&#?[a-zA-Z0-9]+;)/g));
If you wrap the delimiter in parantheses it will be part of the returned array.
string.split(/(<br \/>&#?[a-zA-Z0-9]+);/g);
// returns ["aaaaaa", "<br />†", "bbbb", "<br />‡", "cccc"]
Depending on which part you want to keep change which subgroup you match
string.split(/(<br \/>)&#?[a-zA-Z0-9]+;/g);
// returns ["aaaaaa", "<br />", "bbbb", "<br />", "cccc"]
You could improve the expression by ignoring the case of letters
string.split(/()&#?[a-z0-9]+;/gi);
And you can match for predefined groups like this: \d equals [0-9] and \w equals [a-zA-Z0-9_]. This means your expression could look like this.
string.split(/<br \/>(&#?[a-z\d]+;)/gi);
There is a good Regular Expression Reference on JavaScriptKit.
If you group the split pattern, its match will be kept in the output and it is by design:
If separator is a regular expression with capturing parentheses, then
each time separator matches, the results (including any undefined
results) of the capturing parentheses are spliced into the output
array.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/split#description
You don't need a lookahead or global flag unless your search pattern uses one.
const str = `How much wood would a woodchuck chuck, if a woodchuck could chuck wood?`
const result = str.split(/(\s+)/);
console.log(result);
// We can verify the result
const isSame = result.join('') === str;
console.log({ isSame });
You can use multiple groups. You can be as creative as you like and what remains outside the groups will be removed:
const str = `How much wood would a woodchuck chuck, if a woodchuck could chuck wood?`
const result = str.split(/(\s+)(\w{1,2})\w+/);
console.log(result, result.join(''));
answered it here also JavaScript Split Regular Expression keep the delimiter
use the (?=pattern) lookahead pattern in the regex
example
var string = '500x500-11*90~1+1';
string = string.replace(/(?=[$-/:-?{-~!"^_`\[\]])/gi, ",");
string = string.split(",");
this will give you the following result.
[ '500x500', '-11', '*90', '~1', '+1' ]
Can also be directly split
string = string.split(/(?=[$-/:-?{-~!"^_`\[\]])/gi);
giving the same result
[ '500x500', '-11', '*90', '~1', '+1' ]
I made a modification to jichi's answer, and put it in a function which also supports multiple letters.
String.prototype.splitAndKeep = function(separator, method='seperate'){
var str = this;
if(method == 'seperate'){
str = str.split(new RegExp(`(${separator})`, 'g'));
}else if(method == 'infront'){
str = str.split(new RegExp(`(?=${separator})`, 'g'));
}else if(method == 'behind'){
str = str.split(new RegExp(`(.*?${separator})`, 'g'));
str = str.filter(function(el){return el !== "";});
}
return str;
};
jichi's answers 3rd method would not work in this function, so I took the 4th method, and removed the empty spaces to get the same result.
edit:
second method which excepts an array to split char1 or char2
String.prototype.splitAndKeep = function(separator, method='seperate'){
var str = this;
function splitAndKeep(str, separator, method='seperate'){
if(method == 'seperate'){
str = str.split(new RegExp(`(${separator})`, 'g'));
}else if(method == 'infront'){
str = str.split(new RegExp(`(?=${separator})`, 'g'));
}else if(method == 'behind'){
str = str.split(new RegExp(`(.*?${separator})`, 'g'));
str = str.filter(function(el){return el !== "";});
}
return str;
}
if(Array.isArray(separator)){
var parts = splitAndKeep(str, separator[0], method);
for(var i = 1; i < separator.length; i++){
var partsTemp = parts;
parts = [];
for(var p = 0; p < partsTemp.length; p++){
parts = parts.concat(splitAndKeep(partsTemp[p], separator[i], method));
}
}
return parts;
}else{
return splitAndKeep(str, separator, method);
}
};
usage:
str = "first1-second2-third3-last";
str.splitAndKeep(["1", "2", "3"]) == ["first", "1", "-second", "2", "-third", "3", "-last"];
str.splitAndKeep("-") == ["first1", "-", "second2", "-", "third3", "-", "last"];
An extension function splits string with substring or RegEx and the delimiter is putted according to second parameter ahead or behind.
String.prototype.splitKeep = function (splitter, ahead) {
var self = this;
var result = [];
if (splitter != '') {
var matches = [];
// Getting mached value and its index
var replaceName = splitter instanceof RegExp ? "replace" : "replaceAll";
var r = self[replaceName](splitter, function (m, i, e) {
matches.push({ value: m, index: i });
return getSubst(m);
});
// Finds split substrings
var lastIndex = 0;
for (var i = 0; i < matches.length; i++) {
var m = matches[i];
var nextIndex = ahead == true ? m.index : m.index + m.value.length;
if (nextIndex != lastIndex) {
var part = self.substring(lastIndex, nextIndex);
result.push(part);
lastIndex = nextIndex;
}
};
if (lastIndex < self.length) {
var part = self.substring(lastIndex, self.length);
result.push(part);
};
// Substitution of matched string
function getSubst(value) {
var substChar = value[0] == '0' ? '1' : '0';
var subst = '';
for (var i = 0; i < value.length; i++) {
subst += substChar;
}
return subst;
};
}
else {
result.add(self);
};
return result;
};
The test:
test('splitKeep', function () {
// String
deepEqual("1231451".splitKeep('1'), ["1", "231", "451"]);
deepEqual("123145".splitKeep('1', true), ["123", "145"]);
deepEqual("1231451".splitKeep('1', true), ["123", "145", "1"]);
deepEqual("hello man how are you!".splitKeep(' '), ["hello ", "man ", "how ", "are ", "you!"]);
deepEqual("hello man how are you!".splitKeep(' ', true), ["hello", " man", " how", " are", " you!"]);
// Regex
deepEqual("mhellommhellommmhello".splitKeep(/m+/g), ["m", "hellomm", "hellommm", "hello"]);
deepEqual("mhellommhellommmhello".splitKeep(/m+/g, true), ["mhello", "mmhello", "mmmhello"]);
});
I've been using this:
String.prototype.splitBy = function (delimiter) {
var
delimiterPATTERN = '(' + delimiter + ')',
delimiterRE = new RegExp(delimiterPATTERN, 'g');
return this.split(delimiterRE).reduce((chunks, item) => {
if (item.match(delimiterRE)){
chunks.push(item)
} else {
chunks[chunks.length - 1] += item
};
return chunks
}, [])
}
Except that you shouldn't mess with String.prototype, so here's a function version:
var splitBy = function (text, delimiter) {
var
delimiterPATTERN = '(' + delimiter + ')',
delimiterRE = new RegExp(delimiterPATTERN, 'g');
return text.split(delimiterRE).reduce(function(chunks, item){
if (item.match(delimiterRE)){
chunks.push(item)
} else {
chunks[chunks.length - 1] += item
};
return chunks
}, [])
}
So you could do:
var haystack = "aaaaaa<br />† bbbb<br />‡ cccc"
var needle = '<br \/>&#?[a-zA-Z0-9]+;';
var result = splitBy(haystack , needle)
console.log( JSON.stringify( result, null, 2) )
And you'll end up with:
[
"<br />† bbbb",
"<br />‡ cccc"
]
Most of the existing answers predate the introduction of lookbehind assertions in JavaScript in 2018. You didn't specify how you wanted the delimiters to be included in the result. One typical use case would be sentences delimited by punctuation ([.?!]), where one would want the delimiters to be included at the ends of the resulting strings. This corresponds to the fourth case in the accepted answer, but as noted there, that solution only works for single characters. Arbitrary strings with the delimiters appended at the end can be formed with a lookbehind assertion:
'It is. Is it? It is!'.split(/(?<=[.?!])/)
/* [ 'It is.', ' Is it?', ' It is!' ] */
I know that this is a bit late but you could also use lookarounds
var string = "aaaaaa<br />† bbbb<br />‡ cccc";
var array = string.split(/(?<=<br \/>)/);
console.log(array);
I've also came up with this solution. No regex needed, very readable.
const str = "hello world what a great day today balbla"
const separatorIndex = str.indexOf("great")
const parsedString = str.slice(separatorIndex)
console.log(parsedString)