I have to replace all letters of name on ****.
Example:
Jeniffer -> J****r
I try $(this).text( $(this).text().replace(/([^\w])\//g, "*"))
Also, if name is Ron -> R****n
You can use a regular expression for this, by capturing the first and last letters in a capture group and ignoring all letters between them, then using the capture groups in the replacement:
var updated = name.replace(/^(.).*(.)$/, "$1****$2");
Live Example:
function obscure(name) {
return name.replace(/^(.).*(.)$/, "$1****$2");
}
function test(name) {
console.log(name, "=>", obscure(name));
}
test("Ron");
test("Jeniffer");
But it's perhaps easier without:
var updated = name[0] + "****" + name[name.length - 1];
Live Example:
function obscure(name) {
return name[0] + "****" + name[name.length - 1];;
}
function test(name) {
console.log(name, "=>", obscure(name));
}
test("Ron");
test("Jeniffer");
Both of those do assume the names will be at least two characters long. I pity the fool who tries this on Mr. T's surname.
Since, you need to have four asterisk on each condition, you can create a reusable function that will create this format for you:
function replace(str){
var firstChar = str.charAt(0);
var lastChar = str.charAt(str.length-1);
return firstChar + '****' + lastChar;
}
var str = 'Jeniffer';
console.log(replace(str));
str = 'America';
console.log(replace(str))
Appears that you're looking for regex lookaround
Regex: (?<=\w)(\w+)(?=\w) - group 1 matches all characters which follow one character and followed by another one.
Tests: https://regex101.com/r/PPeEqx/2/
More Info: https://www.regular-expressions.info/lookaround.html
Find first and last chars and append **** to the first one and add the last one:
const firstName = 'Jeniffer';
const result = firstName.match(/^.|.$/gi).reduce((s, c, i) => `${s}${!i ? `${c}****` : c }`, '');
console.log(result);
I am attempting to create a way to convert text with lowercase letters and underscores into text without underscores and the first letter of each word is capitalized.
ex;
options_page = Options Page
At this page: How to make first character uppercase of all words in JavaScript?
I found this regex:
key = key.replace(/(?:_| |\b)(\w)/g, function(key, p1) { return p1.toUpperCase()});
This does everything except replace the underscores with spaces. I have not really tried anything because I am not that familiar with regexpressions.
How can I adjust this regex so it replaces underscores with spaces?
This should do the trick:
function humanize(str) {
var i, frags = str.split('_');
for (i=0; i<frags.length; i++) {
frags[i] = frags[i].charAt(0).toUpperCase() + frags[i].slice(1);
}
return frags.join(' ');
}
console.log(humanize('humpdey_dumpdey'));
// > Humpdey Dumpdey
repl
http://repl.it/OnE
Fiddle:
http://jsfiddle.net/marionebl/nf4NG/
jsPerf:
Most test data: http://jsperf.com/string-transformations
All versions plus _.str: http://jsperf.com/string-transformations/3
Since Lodash 3.1.0, there's a _.startCase([string='']) method that transforms any case into capitalized words (start case):
_.startCase('hello_world'); // returns 'Hello World'
_.startCase('hello-world'); // returns 'Hello World'
_.startCase('hello world'); // returns 'Hello World'
There are other useful methods in the String section of Lodash. Read the documentation here.
These are two different tasks, so two different regexes is the best solution:
key = key.replace(/_/g, ' ').replace(/(?: |\b)(\w)/g, function(key) { return key.toUpperCase()});
To ensure even all capital words is processed. You can add .toLowerCase() before the very first .replace:
console.log('TESTING_WORD'.toLowerCase().replace(/_/g, ' ')
.replace(/(?: |\b)(\w)/g, function(key, p1) {
return key.toUpperCase();
}));
Simply add .replace('_',' ')
Like this
function toCamel(string){
return string.replace(/(?:_| |\b)(\w)/g, function($1){return $1.toUpperCase().replace('_',' ');});
}
Another alternative:
camel = "options_page".replace(/(^|_)(\w)/g, function ($0, $1, $2) {
return ($1 && ' ') + $2.toUpperCase();
});
console.log(camel);
The regular expression:
(^|_) beginning of the input OR "_" ($1)
(\w) a word character (short for [a-zA-Z0-9_]) ($2)
g all occurrences (global)
More about regular expressions : http://www.javascriptkit.com/javatutors/redev.shtml.
Here:
var str = 'Lorem_ipsum_dolor_sit_amet,_consectetur____adipiscing_elit.'
str = str.replace(/_{1,}/g,' ').replace(/(\s{1,}|\b)(\w)/g, function(m, space, letter)
{
return space + letter.toUpperCase();
})
console.log(str);
I am so close to getting this, but it just isn't right.
All I would like to do is remove the character r from a string.
The problem is, there is more than one instance of r in the string.
However, it is always the character at index 4 (so the 5th character).
Example string: crt/r2002_2
What I want: crt/2002_2
This replace function removes both r
mystring.replace(/r/g, '')
Produces: ct/2002_2
I tried this function:
String.prototype.replaceAt = function (index, char) {
return this.substr(0, index) + char + this.substr(index + char.length);
}
mystring.replaceAt(4, '')
It only works if I replace it with another character. It will not simply remove it.
Any thoughts?
var mystring = "crt/r2002_2";
mystring = mystring.replace('/r','/');
will replace /r with / using String.prototype.replace.
Alternatively you could use regex with a global flag (as suggested by Erik Reppen & Sagar Gala, below) to replace all occurrences with
mystring = mystring.replace(/\/r/g, '/');
EDIT:
Since everyone's having so much fun here and user1293504 doesn't seem to be coming back any time soon to answer clarifying questions, here's a method to remove the Nth character from a string:
String.prototype.removeCharAt = function (i) {
var tmp = this.split(''); // convert to an array
tmp.splice(i - 1 , 1); // remove 1 element from the array (adjusting for non-zero-indexed counts)
return tmp.join(''); // reconstruct the string
}
console.log("crt/r2002_2".removeCharAt(4));
Since user1293504 used the normal count instead of a zero-indexed count, we've got to remove 1 from the index, if you wish to use this to replicate how charAt works do not subtract 1 from the index on the 3rd line and use tmp.splice(i, 1) instead.
A simple functional javascript way would be
mystring = mystring.split('/r').join('/')
simple, fast, it replace globally and no need for functions or prototypes
There's always the string functions, if you know you're always going to remove the fourth character:
str.slice(0, 4) + str.slice(5, str.length)
Your first func is almost right. Just remove the 'g' flag which stands for 'global' (edit) and give it some context to spot the second 'r'.
Edit: didn't see it was the second 'r' before so added the '/'. Needs \/ to escape the '/' when using a regEx arg. Thanks for the upvotes but I was wrong so I'll fix and add more detail for people interested in understanding the basics of regEx better but this would work:
mystring.replace(/\/r/, '/')
Now for the excessive explanation:
When reading/writing a regEx pattern think in terms of: <a character or set of charcters> followed by <a character or set of charcters> followed by <...
In regEx <a character or set of charcters> could be one at a time:
/each char in this pattern/
So read as e, followed by a, followed by c, etc...
Or a single <a character or set of charcters> could be characters described by a character class:
/[123!y]/
//any one of these
/[^123!y]/
//anything but one of the chars following '^' (very useful/performance enhancing btw)
Or expanded on to match a quantity of characters (but still best to think of as a single element in terms of the sequential pattern):
/a{2}/
//precisely two 'a' chars - matches identically as /aa/ would
/[aA]{1,3}/
//1-3 matches of 'a' or 'A'
/[a-zA-Z]+/
//one or more matches of any letter in the alphabet upper and lower
//'-' denotes a sequence in a character class
/[0-9]*/
//0 to any number of matches of any decimal character (/\d*/ would also work)
So smoosh a bunch together:
var rePattern = /[aA]{4,8}(Eat at Joes|Joes all you can eat)[0-5]+/g
var joesStr = 'aaaAAAaaEat at Joes123454321 or maybe aAaAJoes all you can eat098765';
joesStr.match(rePattern);
//returns ["aaaAAAaaEat at Joes123454321", "aAaAJoes all you can eat0"]
//without the 'g' after the closing '/' it would just stop at the first match and return:
//["aaaAAAaaEat at Joes123454321"]
And of course I've over-elaborated but my point was simply that this:
/cat/
is a series of 3 pattern elements (a thing followed by a thing followed by a thing).
And so is this:
/[aA]{4,8}(Eat at Joes|Joes all you can eat)[0-5]+/
As wacky as regEx starts to look, it all breaks down to series of things (potentially multi-character things) following each other sequentially. Kind of a basic point but one that took me a while to get past so I've gone overboard explaining it here as I think it's one that would help the OP and others new to regEx understand what's going on. The key to reading/writing regEx is breaking it down into those pieces.
Just fix your replaceAt:
String.prototype.replaceAt = function(index, charcount) {
return this.substr(0, index) + this.substr(index + charcount);
}
mystring.replaceAt(4, 1);
I'd call it removeAt instead. :)
For global replacement of '/r', this code worked for me.
mystring = mystring.replace(/\/r/g,'');
This is improvement of simpleigh answer (omit length)
s.slice(0, 4) + s.slice(5)
let s = "crt/r2002_2";
let o = s.slice(0, 4) + s.slice(5);
let delAtIdx = (s, i) => s.slice(0, i) + s.slice(i + 1); // this function remove letter at index i
console.log(o);
console.log(delAtIdx(s, 4));
let str = '1234567';
let index = 3;
str = str.substring(0, index) + str.substring(index + 1);
console.log(str) // 123567 - number "4" under index "3" is removed
return this.substr(0, index) + char + this.substr(index + char.length);
char.length is zero. You need to add 1 in this case in order to skip character.
Maybe I'm a noob, but I came across these today and they all seem unnecessarily complicated.
Here's a simpler (to me) approach to removing whatever you want from a string.
function removeForbiddenCharacters(input) {
let forbiddenChars = ['/', '?', '&','=','.','"']
for (let char of forbiddenChars){
input = input.split(char).join('');
}
return input
}
Create function like below
String.prototype.replaceAt = function (index, char) {
if(char=='') {
return this.slice(0,index)+this.substr(index+1 + char.length);
} else {
return this.substr(0, index) + char + this.substr(index + char.length);
}
}
To replace give character like below
var a="12346";
a.replaceAt(4,'5');
and to remove character at definite index, give second parameter as empty string
a.replaceAt(4,'');
If it is always the 4th char in yourString you can try:
yourString.replace(/^(.{4})(r)/, function($1, $2) { return $2; });
It only works if I replace it with another character. It will not simply remove it.
This is because when char is equal to "", char.length is 0, so your substrings combine to form the original string. Going with your code attempt, the following will work:
String.prototype.replaceAt = function (index, char) {
return this.substr(0, index) + char + this.substr(index + 1);
// this will 'replace' the character at index with char ^
}
DEMO
You can use this: if ( str[4] === 'r' ) str = str.slice(0, 4) + str.slice(5)
Explanation:
if ( str[4] === 'r' )
Check if the 5th character is a 'r'
str.slice(0, 4)
Slice the string to get everything before the 'r'
+ str.slice(5)
Add the rest of the string.
Minified: s=s[4]=='r'?s.slice(0,4)+s.slice(5):s [37 bytes!]
DEMO:
function remove5thR (s) {
s=s[4]=='r'?s.slice(0,4)+s.slice(5):s;
console.log(s); // log output
}
remove5thR('crt/r2002_2') // > 'crt/2002_2'
remove5thR('crt|r2002_2') // > 'crt|2002_2'
remove5thR('rrrrr') // > 'rrrr'
remove5thR('RRRRR') // > 'RRRRR' (no change)
If you just want to remove single character and
If you know index of a character you want to remove, you can use following function:
/**
* Remove single character at particular index from string
* #param {*} index index of character you want to remove
* #param {*} str string from which character should be removed
*/
function removeCharAtIndex(index, str) {
var maxIndex=index==0?0:index;
return str.substring(0, maxIndex) + str.substring(index, str.length)
}
I dislike using replace function to remove characters from string. This is not logical to do it like that. Usually I program in C# (Sharp), and whenever I want to remove characters from string, I use the Remove method of the String class, but no Replace method, even though it exists, because when I am about to remove, I remove, no replace. This is logical!
In Javascript, there is no remove function for string, but there is substr function. You can use the substr function once or twice to remove characters from string. You can make the following function to remove characters at start index to the end of string, just like the c# method first overload String.Remove(int startIndex):
function Remove(str, startIndex) {
return str.substr(0, startIndex);
}
and/or you also can make the following function to remove characters at start index and count, just like the c# method second overload String.Remove(int startIndex, int count):
function Remove(str, startIndex, count) {
return str.substr(0, startIndex) + str.substr(startIndex + count);
}
and then you can use these two functions or one of them for your needs!
Example:
alert(Remove("crt/r2002_2", 4, 1));
Output: crt/2002_2
Achieving goals by doing techniques with no logic might cause confusions in understanding of the code, and future mistakes, if you do this a lot in a large project!
The following function worked best for my case:
public static cut(value: string, cutStart: number, cutEnd: number): string {
return value.substring(0, cutStart) + value.substring(cutEnd + 1, value.length);
}
The shortest way would be to use splice
var inputString = "abc";
// convert to array and remove 1 element at position 4 and save directly to the array itself
let result = inputString.split("").splice(3, 1).join();
console.log(result);
This problem has many applications. Tweaking #simpleigh solution to make it more copy/paste friendly:
function removeAt( str1, idx) {
return str1.substr(0, idx) + str1.substr(idx+1)
}
console.log(removeAt('abbcdef', 1)) // prints: abcdef
Using [index] position for removing a specific char (s)
String.prototype.remplaceAt = function (index, distance) {
return this.slice(0, index) + this.slice(index + distance, this.length);
};
credit to https://stackoverflow.com/users/62576/ken-white
So basically, another way would be to:
Convert the string to an array using Array.from() method.
Loop through the array and delete all r letters except for the one with index 1.
Convert array back to a string.
let arr = Array.from("crt/r2002_2");
arr.forEach((letter, i) => { if(letter === 'r' && i !== 1) arr[i] = "" });
document.write(arr.join(""));
In C# (Sharp), you can make an empty character as '\0'.
Maybe you can do this:
String.prototype.replaceAt = function (index, char) {
return this.substr(0, index) + char + this.substr(index + char.length);
}
mystring.replaceAt(4, '\0')
Search on google or surf on the interent and check if javascript allows you to make empty characters, like C# does. If yes, then learn how to do it, and maybe the replaceAt function will work at last, and you'll achieve what you want!
Finally that 'r' character will be removed!
Am I missing something in my code? It seems to only grab the first letter, and the while loop, doesn't go onto the next word. So what could I be missing?
function acr(s){
var words, acronym, nextWord;
words = s.split();
acronym= "";
index = 0
while (index<words.length) {
nextWord = words[index];
acronym = acronym + nextWord.charAt(0);
index = index + 1 ;
}
return acronym
}
If you only care about IE9+ then the answer can be made shorter:
function acronym(text) {
return text
.split(/\s/)
.reduce(function(accumulator, word) {
return accumulator + word.charAt(0);
}, '');
}
console.log(acronym('three letter acronym'));
If you can use arrow functions then it can be made shorter still:
function acronym(text) {
return text
.split(/\s/)
.reduce((accumulator, word) => accumulator + word.charAt(0), '');
}
console.log(acronym('three letter acronym'));
Add the separator to the split:
function acr(s){
var words, acronym, nextWord;
words = s.split(' ');
acronym= "";
index = 0
while (index<words.length) {
nextWord = words[index];
acronym = acronym + nextWord.charAt(0);
index = index + 1 ;
}
return acronym
}
JS Fiddle demo;
Revised the above to make it a little more demonstrative, and also interactive: JS Fiddle demo.
Edited to add references and explanation:
Because no separator was supplied the string remains un-split; therefore the while was operating correctly (as words.length is equal to 1), and so returns only the first letter of the string:
[Separator] specifies the character to use for separating the string. The separator is treated as a string or a regular expression. If separator is omitted, the array returned contains one element consisting of the entire string.
Reference:
split(), at MDC Docs
You forgot to split on whitespace:
words = s.split(/\s/);
You can have this in even lesser code. Try this
s.match(/\b(\w)/g).join("").toUpperCase()
I have searched for solution but did not find yet.
I have the following string.
1. hello
2. HELLO
3. hello_world
4. HELLO_WORLD
5. Hello World
I want to convert them to following:
1. Hello
2. Hello
3. HelloWorld
4. HelloWorld
5. HelloWorld
If there is No space and underscore in string just uppercase first and all others to lowercase. If words are separated by underscore or space then Uppercase first letter of each word and remove space and underscore. How can I do this in JavaScript.
Thanks
Here is a regex solution:
First lowercase the string:
str = str.toLowerCase();
Replace all _ and spaces and first characters in a word with upper case character:
str = str.replace(/(?:_| |\b)(\w)/g, function(str, p1) { return p1.toUpperCase()})
DEMO
Update: Less steps ;)
Explanation:
/ // start of regex
(?: // starts a non capturing group
_| |\b // match underscore, space, or any other word boundary character
// (which in the end is only the beginning of the string ^)
) // end of group
( // start capturing group
\w // match word character
) // end of group
/g // and of regex and search the whole string
The value of the capturing group is available as p1 in the function, and the whole expression is replaced by the return value of the function.
You could do something like this:
function toPascalCase(str) {
var arr = str.split(/\s|_/);
for(var i=0,l=arr.length; i<l; i++) {
arr[i] = arr[i].substr(0,1).toUpperCase() +
(arr[i].length > 1 ? arr[i].substr(1).toLowerCase() : "");
}
return arr.join("");
}
You can test it out here, the approach is pretty simple, .split() the string into an array when finding either whitespace or an underscore. Then loop through the array, upper-casing the first letter, lower-casing the rest...then take that array of title-case words and .join() it together into one string again.
function foo(str) {
return $(str.split(/\s|_/)).map(function() {
return this.charAt(0).toUpperCase() + this.slice(1).toLowerCase();
}).get().join("");
}
Working demo: http://jsfiddle.net/KSJe3/3/
(I used Nicks regular expression in the demo)
Edit: Another version of the code - I replaced map() with $.map():
function foo(str) {
return $.map(str.split(/\s|_/), function(word) {
return word.charAt(0).toUpperCase() + word.slice(1).toLowerCase();
}).join("");
}
Working demo: http://jsfiddle.net/KSJe3/4/
An ES6 / functional update of #NickCraver's answer. As with #NickCraver's answer this function will handle multiple spaces / underscores properly by filtering them out.
const pascalWord = x => x[0].toUpperCase() + x.slice(1).toLowerCase();
const toPascalCase2 = (str) => (
str.split(/\s|_/)
.filter(x => x)
.map(pascalWord)
.join('')
);
const tests = [
'hello',
'HELLO',
'hello_world',
'HELLO_WORLD',
'Hello World',
'HELLO__WORLD__',
'Hello World_',
].map(toPascalCase2).join('<br>');
document.write(tests);
var city = city.replace(/\s+/g,' ') //replace all spaceses to singele speace
city = city.replace(/\b\w/g,city => city .toUpperCase()) //after speace letter convert capital