问题
What is the best approach to capitalize words in a string?
回答1:
String.prototype.capitalize = function() {
return this.replace(/(?:^|\s)\S/g, function(a) { return a.toUpperCase(); });
};
Usage:
'your string'.capitalize(); // -> 'Your String'
fixes Marco Demaio's solution where first letter with a space preceding is not capitalized.
' javascript'.capitalize(); // -> ' Javascript'can handle national symbols and accented letters.
'бабушка курит трубку'.capitalize(); // -> 'Бабушка Курит Трубку' 'località àtilacol'.capitalize() // -> 'Località Àtilacol'
ADD-ON I find it useful
String.prototype.capitalize = function(lower) {
return (lower ? this.toLowerCase() : this).replace(/(?:^|\s)\S/g, function(a) { return a.toUpperCase(); });
};
'javaSCrIPT'.capitalize(); // -> 'JavaSCrIPT'
'javaSCrIPT'.capitalize(true); // -> 'Javascript'
回答2:
The shortest implementation for capitalizing words within a string is the following using ES6's arrow functions:
'your string'.replace(/\b\w/g, l => l.toUpperCase())
// => 'Your String'
ES5 compatible implementation:
'your string'.replace(/\b\w/g, function(l){ return l.toUpperCase() })
// => 'Your String'
The regex basically matches the first letter of each word within the given string and transforms only that letter to uppercase:
- \b matches a word boundary (the beginning or ending of word);
- \w matches the following meta-character [a-zA-Z0-9].
For non-ASCII characters refer to this solution instead
'ÿöur striñg'.replace(/(^|\s)\S/g, l => l.toUpperCase())
This regex matches the first letter and every non-whitespace letter preceded by whitespace within the given string and transforms only that letter to uppercase:
- \s matches a whitespace character
- \S matches a non-whitespace character
- (x|y) matches any of the specified alternatives
A non-capturing group could have been used here as follows /(?:^|\s)\S/g though the g flag within our regex wont capture sub-groups by design anyway.
Cheers!
回答3:
function capitalize(s){
return s.toLowerCase().replace( /\b./g, function(a){ return a.toUpperCase(); } );
};
capitalize('this IS THE wOrst string eVeR');
output: "This Is The Worst String Ever"
Update:
It appears this solution supersedes mine: https://stackoverflow.com/a/7592235/104380
回答4:
The answer provided by vsync works as long as you don't have accented letters in the input string.
I don't know the reason, but apparently the \b in regexp matches also accented letters (tested on IE8 and Chrome), so a string like "località" would be wrongly capitalized converted into "LocalitÀ" (the à letter gets capitalized cause the regexp thinks it's a word boundary)
A more general function that works also with accented letters is this one:
String.prototype.toCapitalize = function()
{
return this.toLowerCase().replace(/^.|\s\S/g, function(a) { return a.toUpperCase(); });
}
You can use it like this:
alert( "hello località".toCapitalize() );
回答5:
Since everyone has given you the JavaScript answer you've asked for, I'll throw in that the CSS property text-transform: capitalize will do exactly this.
I realize this might not be what you're asking for - you haven't given us any of the context in which you're running this - but if it's just for presentation, I'd definitely go with the CSS alternative.
回答6:
John Resig (of jQuery fame ) ported a perl script, written by John Gruber, to JavaScript. This script capitalizes in a more intelligent way, it doesn't capitalize small words like 'of' and 'and' for example.
You can find it here: Title Capitalization in JavaScript
回答7:
Using JavaScript and html
String.prototype.capitalize = function() {
return this.replace(/(^|\s)([a-z])/g, function(m, p1, p2) {
return p1 + p2.toUpperCase();
});
};<form name="form1" method="post">
<input name="instring" type="text" value="this is the text string" size="30">
<input type="button" name="Capitalize" value="Capitalize >>" onclick="form1.outstring.value=form1.instring.value.capitalize();">
<input name="outstring" type="text" value="" size="30">
</form>Basically, you can do string.capitalize() and it'll capitalize every 1st letter of each word.
Source: http://www.mediacollege.com/internet/javascript/text/case-capitalize.html
回答8:
If you're using lodash in your JavaScript application, You can use _.capitalize:
console.log( _.capitalize('ÿöur striñg') );
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js"></script>回答9:
A concise ES6 way of doing it might look something like this.
const capitalizeFirstLetter = s => s.charAt(0).toUpperCase() + s.slice(1)
This only uppercases the first letter and doesn't affect the rest of the sentence's casing.
回答10:
My solution:
String.prototype.toCapital = function () {
return this.toLowerCase().split(' ').map(function (i) {
if (i.length > 2) {
return i.charAt(0).toUpperCase() + i.substr(1);
} else {
return i;
}
}).join(' ');
};
Example:
'álL riGht'.toCapital();
// Returns 'Áll Right'
回答11:
This should cover most basic use cases.
const capitalize = (str) => {
if (typeof str !== 'string') {
throw Error('Feed me string')
} else if (!str) {
return ''
} else {
return str
.split(' ')
.map(s => {
if (s.length == 1 ) {
return s.toUpperCase()
} else {
const firstLetter = s.split('')[0].toUpperCase()
const restOfStr = s.substr(1, s.length).toLowerCase()
return firstLetter + restOfStr
}
})
.join(' ')
}
}
capitalize('THIS IS A BOOK') // => This Is A Book
capitalize('this is a book') // => This Is A Book
capitalize('a 2nd 5 hour boOk thIs weEk') // => A 2nd 5 Hour Book This Week
Edit: Improved readability of mapping.
回答12:
Ivo's answer is good, but I prefer to not match on \w because there's no need to capitalize 0-9 and A-Z. We can ignore those and only match on a-z.
'your string'.replace(/\b[a-z]/g, match => match.toUpperCase())
// => 'Your String'
It's the same output, but I think clearer in terms of self-documenting code.
回答13:
http://www.mediacollege.com/internet/javascript/text/case-capitalize.html is one of many answers out there.
Google can be all you need for such problems.
A naïve approach would be to split the string by whitespace, capitalize the first letter of each element of the resulting array and join it back together. This leaves existing capitalization alone (e.g. HTML stays HTML and doesn't become something silly like Html). If you don't want that affect, turn the entire string into lowercase before splitting it up.
回答14:
This code capitalize words after dot:
function capitalizeAfterPeriod(input) {
var text = '';
var str = $(input).val();
text = convert(str.toLowerCase().split('. ')).join('. ');
var textoFormatado = convert(text.split('.')).join('.');
$(input).val(textoFormatado);
}
function convert(str) {
for(var i = 0; i < str.length; i++){
str[i] = str[i].split('');
if (str[i][0] !== undefined) {
str[i][0] = str[i][0].toUpperCase();
}
str[i] = str[i].join('');
}
return str;
}
回答15:
I like to go with easy process. First Change string into Array for easy iterating, then using map function change each word as you want it to be.
function capitalizeCase(str) {
var arr = str.split(' ');
var t;
var newt;
var newarr = arr.map(function(d){
t = d.split('');
newt = t.map(function(d, i){
if(i === 0) {
return d.toUpperCase();
}
return d.toLowerCase();
});
return newt.join('');
});
var s = newarr.join(' ');
return s;
}
回答16:
Jquery or Javascipt doesn't provide a built-in method to achieve this.
CSS test transform (text-transform:capitalize;) doesn't really capitalize the string's data but shows a capitalized rendering on the screen.
If you are looking for a more legit way of achieving this in the data level using plain vanillaJS, use this solution =>
var capitalizeString = function (word) {
word = word.toLowerCase();
if (word.indexOf(" ") != -1) { // passed param contains 1 + words
word = word.replace(/\s/g, "--");
var result = $.camelCase("-" + word);
return result.replace(/-/g, " ");
} else {
return $.camelCase("-" + word);
}
}
回答17:
Use This:
String.prototype.toTitleCase = function() {
return this.charAt(0).toUpperCase() + this.slice(1);
}
let str = 'text';
document.querySelector('#demo').innerText = str.toTitleCase();<div class = "app">
<p id = "demo"></p>
</div>回答18:
You can use the following to capitalize words in a string:
function capitalizeAll(str){
var partes = str.split(' ');
var nuevoStr = "";
for(i=0; i<partes.length; i++){
nuevoStr += " "+partes[i].toLowerCase().replace(/\b\w/g, l => l.toUpperCase()).trim();
}
return nuevoStr;
}
回答19:
This solution dose not use regex, supports accented characters and also supported by almost every browser.
function capitalizeIt(str) {
if (str && typeof(str) === "string") {
str = str.split(" ");
for (var i = 0, x = str.length; i < x; i++) {
if (str[i]) {
str[i] = str[i][0].toUpperCase() + str[i].substr(1);
}
}
return str.join(" ");
} else {
return str;
}
}
Usage:
console.log(capitalizeIt('çao 2nd inside Javascript programme'));
Output:
Çao 2nd Inside Javascript Programme
来源：https://stackoverflow.com/questions/2332811/capitalize-words-in-string