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JS Split multiple delimiters and get delimiters into input value

I'm asking you today for a little problem :
I have to live control capitalization/no capitalization with js on an input text field like this:
1st character of the entire string must be uppercase
1st character of each word (after space or hyphen) is free (lowercase or uppercase allowed)
All the nother characters must be lowercase
Desired Output: Grand-Father is Nice
I'm not a specialist of JS, i'm using split function, here is my code :
$('#name').on('input change',function() {
var arr1 = $(this).val().split(/[- ]/);
var result1 = "";
for (var x=0; x<arr1.length; x++)
result1+=arr1[x].substring(0,1)+arr1[x].substring(1).toLowerCase()+" ";
var res1 = result1.substring(0, result1.length-1);
var _txt = res1.charAt(0).toUpperCase() + res1.slice(1);
$('#name').val(_txt);
});
The script works but I would like to output the real delimiter found in string, even if it's a space " " or hyphen "-". Actually i can show only space. How can i solve it ?
Actual output: Grand Father is Nice
Any help would be appreciated.
Thank you!

User String.replace() with a RegExp and a callback.
If you know what are your delimiters, you can search for all characters that are no the delimiters, and format them:
var input = 'ègrand-Father is NièCe';
var d = '[^\s\-]'; // not space or dash
var result = input.replace(new RegExp('('+ d +')(' + d + '+)', 'g'), function(m, p1, p2, i) {
var end = p2.toLowerCase();
var start = i === 0 ? p1.toUpperCase() : p1;
return start + end;
});
console.log(result);
If the target browsers support it (Chrome does) or you use a transpiler, such as Babel (plugin), you can use Unicode property escapes in regular expressions (\p):
var input = 'ègrand-Father is NièCe';
var result = input.replace(/(\p{L})(\p{L}+)/gu, function(m, p1, p2, i) {
var end = p2.toLowerCase();
var start = i === 0 ? p1.toUpperCase() : p1;
return start + end;
});
console.log(result);

I'm not entirely sure what your aim is, but let's give it a shot.
This is how you can make all non-first letters be lowercase
let sentence = "this is wRoNg SenTEnce."
sentence.split(" ").map(word => word.charAt(0) + word.slice(1).toLowerCase()).join(" ")
This is how you can make first letter capital:
let sentence = "also Wrong sentence"
sentence.charAt(0).toUpperCase()

Capitalize first letter of each word in JS

I'm learning how to capitalize the first letter of each word in a string and for this solution I understand everything except the word.substr(1) portion. I see that it's adding the broken string but how does the (1) work?
function toUpper(str) {
return str
.toLowerCase()
.split(' ')
.map(function(word) {
return word[0].toUpperCase() + word.substr(1);
})
.join(' ');
}
console.log(toUpper("hello friend"))

The return value contain 2 parts:
return word[0].toUpperCase() + word.substr(1);
1) word[0].toUpperCase(): It's the first capital letter
2) word.substr(1) the whole remain word except the first letter which has been capitalized. This is document for how substr works.
Refer below result if you want to debug:
function toUpper(str) {
return str
.toLowerCase()
.split(' ')
.map(function(word) {
console.log("First capital letter: "+word[0]);
console.log("remain letters: "+ word.substr(1));
return word[0].toUpperCase() + word.substr(1);
})
.join(' ');
}
console.log(toUpper("hello friend"))

Or you could save a lot of time and use Lodash
Look at
https://lodash.com/docs/4.17.4#startCase -added/edited-
https://lodash.com/docs/4.17.4#capitalize
Ex.
-added/edited-
You may what to use startCase, another function for capitalizing first letter of each word.
_.startCase('foo bar');
// => 'Foo Bar'
and capitalize for only the first letter on the sentence
_.capitalize('FRED');
// => 'Fred'
Lodash is a beautiful js library made to save you a lot of time.
There you will find a lot of time saver functions for strings, numbers, arrays, collections, etc.
Also you can use it on client or server (nodejs) side, use bower or node, cdn or include it manually.

Here is a quick code snippet. This code snippet will allow you to capitalize the first letter of a string using JavaScript.
function capitlizeText(word)
{
return word.charAt(0).toUpperCase() + word.slice(1);
}

The regexp /\b\w/ matches a word boundary followed by a word character. You can use this with the replace() string method to match then replace such characters (without the g (global) regexp flag only the first matching char is replaced):
> 'hello my name is ...'.replace(/\b\w/, (c) => c.toUpperCase());
'Hello my name is ...'
> 'hello my name is ...'.replace(/\b\w/g, (c) => c.toUpperCase());
'Hello My Name Is ...'

function titleCase(str) {
return str.toLowerCase().split(' ').map(x=>x[0].toUpperCase()+x.slice(1)).join(' ');
}
titleCase("I'm a little tea pot");
titleCase("sHoRt AnD sToUt");

The major part of the answers explains to you how works the substr(1). I give to you a better aproach to resolve your problem
function capitalizeFirstLetters(str){
return str.toLowerCase().replace(/^\w|\s\w/g, function (letter) {
return letter.toUpperCase();
})
}
Explanation:
- First convert the entire string to lower case
- Second check the first letter of the entire string and check the first letter that have a space character before and replaces it applying .toUpperCase() method.
Check this example:
function capitalizeFirstLetters(str){
return str.toLowerCase().replace(/^\w|\s\w/g, function (letter) {
return letter.toUpperCase();
})
}
console.log(capitalizeFirstLetters("a lOt of words separated even much spaces "))

Consider an arrow function with an implicit return:
word => `${word.charAt(0).toUpperCase()}${word.slice(1).toLowerCase()}`
This will do it in one line.

Using ES6
let captalizeWord = text => text.toLowerCase().split(' ').map( (i, j) => i.charAt(0).toUpperCase()+i.slice(1)).join(' ')
captalizeWord('cool and cool')

substr is a function that returns (from the linked MDN) a new string containing the extracted section of the given string (starting from the second character in your function). There is a comment on the polyfill implementation as well, which adds Get the substring of a string.

function titlecase(str){
let titlecasesentence = str.split(' ');
titlecasesentence = titlecasesentence.map((word)=>{
const firstletter = word.charAt(0).toUpperCase();
word = firstletter.concat(word.slice(1,word.length));
return word;
});
titlecasesentence = titlecasesentence.join(' ');
return titlecasesentence;
}
titlecase('this is how to capitalize the first letter of a word');

const capitalize = str => {
if (typeof str !== 'string') {
throw new Error('Invalid input: input must of type "string"');
}
return str
.trim()
.replace(/ {1,}/g, ' ')
.toLowerCase()
.split(' ')
.map(word => word[0].toUpperCase() + word.slice(1))
.join(' ');
};
sanitize the input string with trim() to remove whitespace from the leading and trailing ends
replace any extra spaces in the middle with a RegExp
normalize and convert it all toLowerCase() letters
convert the string to an array split on spaces
map that array into an array of capitalized words
join(' ') the array with spaces and return the newly capitalized string

Whole sentence will be capitalize only by one line
"my name is John".split(/ /g).map(val => val[0].toUpperCase() + val.slice(1)).join(' ')
Output "My Name Is John"

A nice simple solution, using pure JavaScript. JSFiddle
function initCap(s) {
var result = '';
if ((typeof (s) === 'undefined') || (s == null)) {
return result;
}
s = s.toLowerCase();
var words = s.split(' ');
for (var i = 0; i < words.length; ++i) {
result += (i > 0 ? ' ' : '') +
words[i].substring(0, 1).toUpperCase() +
words[i].substring(1);
}
return result;
}

Here is an example of how substr works: When you pass in a number, it takes a portion of the string based on the index you provided:
console.log('Testing string'.substr(0)); // Nothing different
console.log('Testing string'.substr(1)); // Starts from index 1 (position 2)
console.log('Testing string'.substr(2));
So, they are taking the first letter of each word, capitalizing it, and then adding on the remaining of the word. Ance since you are only capitalizing the first letter, the index to start from is always 1.

In word.substr(i), the param means the index of the word. This method cuts the word from the letter whose index equals i to the end of the word.
You can also add another param like word.substr(i, len), where len means the length of the character segmentation. For example:
'abcde'.substr(1, 2) → bc.

function toTitleCase(str)
{
return str.replace(/\w\S*/g, function(txt){return
txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase();});
}

Just map through if an array set the first letter as uppercase and concatenate with other letters from index 1.
The array isn't your case here.
const capitalizeNames = (arr) => {
arr.map((name) => {
let upper = name[0].toUpperCase() + name.substr(1)
console.log(upper)
})
}

Here's another clean way of Capitalizing sentences/names/... :
const capitalizeNames =(name)=>{
const names = name.split(' ') // ['kouhadi','aboubakr',essaaddik']
const newCapName = [] // declaring an empty array
for (const n of names){
newCapName.push(n.replace(n[0], n[0].toUpperCase()));
}
return newCapName.join(' ')
}
capitalizeNames('kouhadi aboubakr essaaddik'); // 'Kouhadi Aboubakr Essaaddik'

You could use these lines of code:
function toUpper(str) {
return [str.split('')[0].toUpperCase(), str.split('').slice(1, str.split('').length).join("")].join("")
}
Basically it will split all characters, slice it, create a new array without the first entry/character and replace the first entry/character with an uppercase verion of the character.
(Yes, this was tested and it works on Edge, Chrome and newer versions of Internet Explorer.)
This is probably not the greatest answer, but hopefully it works well enough for you.

How to account for punctuation and uppercase while counting the number of occurrences of a string in a sentence

I'm writing a function but cannot figure out how to account for upper case letter and punctuation.
My function is :
function countWords(word, string) {
var subStr = string.split(word);
return subStr.length - 1;
}
And it works when I try to test is with wordCount("hey","this is code hey"), but not if I try ("HEY", "this is code hey")
I tried
var subStr= string.toUpperCase().split(word)
but it will not work with lower case letters anymore.

Why can't you try like this.
function countWords(word, string) {
word= word.toLowerCase();
string=string.toLowerCase();
var subStr = string.split(word);
return subStr.length - 1;
}
So that whatever values we sent it will be converted into lower case then it will split.
Does it makes sense right?

Try this :
function countWords(word, string) {
var subStr = string.toLowerCase().split(word.toLowerCase());
return subStr.length - 1;
}
$(document).ready(function(){
$('#result').html(countWords("HEY","this is code hey"));
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div id="result"></div>

Try sending the parameter to either all upper or lower cases first so that it matches the case of the string you are comparing it to. For example,
function countWords(word.toLowerCase, string.toLowerCase)
That way the search is evaluated regardless of case.

You could use a regex with the i and g modifier (case insensitive/match all) and match, then return the length:
function wordCount(search, txt) {
var regex = new RegExp("\\W" + search + "\\W|\\W" + search, "ig");
var match = txt.match(regex);
return match ? match.length : 0;
}
console.log(wordCount("hey","this is code heyHey HEY hey")); // 2
If you want to have heyHey as 2 matches, simply remove |\\W" + search from the regex

Replace string between second set of [ and ]

I am learning regex, and I got a doubt. Let's consider
var s = "YYYN[1-20]N[]NYY";
Now, I want to replace/insert the '1-8' between [ and ] at its second occurrence.
Then output should be
YYYN[1-20]N[1-8]NYY
For that I had tried using replace and passing a function through it as shown below:
var nth = 0;
s = s.replace(/\[([^)]+)\]/g, function(match, i, original) {
nth++;
return (nth === 1) ? "1-8" : match;
});
alert(s); // But It wont work
I think that regex is not matchIing the string that I am using.
How can I fix it?

You regex \[([^)]+)\] will not match empty square brackets since + requires at least 1 character other than ). I guess you wanted to write \[[^\]]*\].
Here is a fix for your solution:
var s = "YYYN[1-20]N[]NYY";
var nth = 0;
s = s.replace(/\[[^\]]*\]/g, function (match, i, original) {
nth++;
return (nth !== 1) ? "[1-8]" : match;
});
alert(s);
Here is another way of doing it:
var s = "YYYN[1-20]N[]NYY";
var nth = 0;
s = s.replace(/(.*)\[\]/, "$1[1-8]");
alert(s);
The regex (.*)\[\] matches and captures into Group 1 greedily as much text as possible (thus we get the last set of empty []), and then matches empty square brackets. Then we restore the text before [] with $1 backreference and add out string 1-8.

If it’s only two occurences of square brackets, then this will work:
/(.*\[.*?\].*\[).*?(\].*)/
This RegEx has “YYYN[1-20]N[” as the first capturing group and “]NYY” as the second.

I suggest using simple split and join operations:
var s = "YYYN[1-20]N[]NYY";
var arr = s.split(/\[/)
arr[2] = '1-8' + arr[2]
var r = arr.join('[')
//=> YYYN[1-20]N[1-8]NYY

You can use following regex :
var s = "YYYN[1-20]N[]NYY";
var nth = 0;
s = s.replace(/([^[]+\[(?:[^[]+)\][^[]+)\[[^[]+\](.+)/, "$1[1-8]$2");
alert(s);
The first part ([^[]+\[([^[]+)\][^[]+) will match a string contain first sub-string between []. and \[[^[]+\] would be the second one which you want and the last part (.+?) match the rest of your string.

Javascript: Returning the last word in a string

right to it:
I have a words string which has two words in it, and i need to return the last word. They are seperated by a " ". How do i do this?
function test(words) {
var n = words.indexOf(" ");
var res = words.substring(n+1,-1);
return res;
}
I've been told to use indexOf and substring but it's not required. Anyone have an easy way to do this? (with or without indexOf and substring)

Try this:
you can use words with n word length.
example:
words = "Hello World";
words = "One Hello World";
words = "Two Hello World";
words = "Three Hello World";
All will return same value: "World"
function test(words) {
var n = words.split(" ");
return n[n.length - 1];
}

You could also:
words.split(" ").pop();
Just chaining the result (array) of the split function and popping the last element would do the trick in just one line :)

var data = "Welcome to Stack Overflow";
console.log(data.split(" ").splice(-1));
Output
[ 'Overflow' ]
This works even if there is no space in the original string, so you can straight away get the element like this
var data = "WelcometoStackOverflow";
console.log(data.split(" ").splice(-1)[0]);
Output
WelcometoStackOverflow

You want the last word, which suggests lastIndexOf may be more efficient for you than indexOf. Further, slice is also a method available to Strings.
var str = 'foo bar fizz buzz';
str.slice(
str.lastIndexOf(' ') + 1
); // "buzz"
See this jsperf from 2011 showing the split vs indexOf + slice vs indexOf + substring and this perf which shows lastIndexOf is about the same efficiency as indexOf, it mostly depends on how long until the match happens.

To complete Jyoti Prakash, you could add multiple separators (\s|,) to split your string (via this post)
Example:
function lastWord(words) {
var n = words.split(/[\s,]+/) ;
return n[n.length - 1];
}
Note: regex \s means whitespace characters : A space character, A tab character, A carriage return character, A new line character, A vertical tab character, A form feed character
snippet
var wordsA = "Hello Worlda"; // tab
var wordsB = "One Hello\nWorldb";
var wordsC = "Two,Hello,Worldc";
var wordsD = "Three Hello Worldd";
function lastWord(words) {
var n = words.split(/[\s,]+/);
return n[n.length - 1];
}
$('#A').html( lastWord(wordsA) );
$('#B').html( lastWord(wordsB) );
$('#C').html( lastWord(wordsC) );
$('#D').html( lastWord(wordsD) );
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
A:<span id="A"></span><br/>
B:<span id="B"></span><br/>
C:<span id="C"></span><br/>
D:<span id="D"></span><br/>

Adding from the accepted answer, if the input string is "Hello World " (note the extra space at the end), it will return ''. The code below should anticipate in case user fat-fingered " ":
var lastWord= function(str) {
if (str.trim() === ""){
return 0;
} else {
var splitStr = str.split(' ');
splitStr = splitStr.filter(lengthFilter);
return splitStr[splitStr.length - 1];
}
};
var lengthFilter = function(str){
return str.length >= 1;
};

Easiest way is to use slice method:-
For example:-
let words = "hello world";
let res = words.slice(6,13);
console.log(res);

/**
* Get last word from a text
* #param {!string} text
* #return {!string}
*/
function getLastWord(text) {
return text
.split(new RegExp("[" + RegExp.quote(wordDelimiters + sentenceDelimiters) + "]+"))
.filter(x => !!x)
.slice(-1)
.join(" ");
}

According to me the easiest way is:
lastName.trim().split(" ").slice(-1)
It will give the last word in a phrase, even if there are trailing spaces.
I used it to show the last name initials. I hope it works for you too.

Use split()
function lastword(words){
array = words.split(' ');
return array[1]
}

Its pretty straight forward.
You have got two words separated by space.
Lets break the string into array using split() method.
Now your array has two elements with indices 0 and 1.
Alert the element with index 1.
var str="abc def";
var arr=str.split(" ");
alert(arr[1]);