ES6内衬

const toTitleCase = string => string.split(' ').map((word) => [word[0].toUpperCase(), ...word.substr(1)].join('')).join(' ');

这里有一个紧凑的解决方案:

function Title_Case(phrase) 
{
  var revised = phrase.charAt(0).toUpperCase();

  for ( var i = 1; i < phrase.length; i++ ) {

    if (phrase.charAt(i - 1) == " ") {
     revised += phrase.charAt(i).toUpperCase(); }
    else {
     revised += phrase.charAt(i).toLowerCase(); }

   }

return revised;
}

与John Resig的解决方案一样功能齐全，但作为一行程序:(基于此github项目)

function toTitleCase(e){var t=/^(a|an|and|as|at|but|by|en|for|if|in|of|on|or|the|to|vs?\.?|via)$/i;return e.replace(/([^\W_]+[^\s-]*) */g,function(e,n,r,i){return r>0&&r+n.length!==i.length&&n.search(t)>-1&&i.charAt(r-2)!==":"&&i.charAt(r-1).search(/[^\s-]/)<0?e.toLowerCase():n.substr(1).search(/[A-Z]|\../)>-1?e:e.charAt(0).toUpperCase()+e.substr(1)})};

console.log( toTitleCase( "ignores mixed case words like iTunes, and allows AT&A and website.com/address etc..." ) );

下面是我的函数，它转换为标题大小写，但也保留了定义的首字母缩写为大写，小词为小写:

String.prototype.toTitleCase = function() {
  var i, j, str, lowers, uppers;
  str = this.replace(/([^\W_]+[^\s-]*) */g, function(txt) {
    return txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase();
  });

  // Certain minor words should be left lowercase unless 
  // they are the first or last words in the string
  lowers = ['A', 'An', 'The', 'And', 'But', 'Or', 'For', 'Nor', 'As', 'At', 
  'By', 'For', 'From', 'In', 'Into', 'Near', 'Of', 'On', 'Onto', 'To', 'With'];
  for (i = 0, j = lowers.length; i < j; i++)
    str = str.replace(new RegExp('\\s' + lowers[i] + '\\s', 'g'), 
      function(txt) {
        return txt.toLowerCase();
      });

  // Certain words such as initialisms or acronyms should be left uppercase
  uppers = ['Id', 'Tv'];
  for (i = 0, j = uppers.length; i < j; i++)
    str = str.replace(new RegExp('\\b' + uppers[i] + '\\b', 'g'), 
      uppers[i].toUpperCase());

  return str;
}

例如:

"TO LOGIN TO THIS SITE and watch tv, please enter a valid id:".toTitleCase();
// Returns: "To Login to This Site and Watch TV, Please Enter a Valid ID:"

如果你想使用NPM库，请查看title-case:

安装:

npm install title-case --save

用法:

import { titleCase } from "title-case";

titleCase("string"); //=> "String"
titleCase("follow step-by-step instructions"); //=> "Follow Step-by-Step Instructions"

String.prototype.capitalize = function() {
    return this.toLowerCase().split(' ').map(capFirst).join(' ');
    function capFirst(str) {
        return str.length === 0 ? str : str[0].toUpperCase() + str.substr(1);
    }
}

用法:

"hello world".capitalize()