请检查下面的代码。

function titleCase(str) {
  var splitStr = str.toLowerCase().split(' ');
  var nstr = ""; 
  for (var i = 0; i < splitStr.length; i++) {
    nstr +=  (splitStr[i].charAt(0).toUpperCase()+ splitStr[i].slice(1) + " 
    ");
  }
  console.log(nstr);
}

var strng = "this is a new demo for checking the string";
titleCase(strng);

这是你可以用map函数做的，它做的和接受的答案一样，但是没有for循环。因此，可以节省几行代码。

函数titleCase(text) { If (!text)返回文本; If (typeof text !== 'string')抛出"无效参数"; 返回text.toLowerCase()。(' ')。Map (value => { return value.charAt(0).toUpperCase() + value.substring(1); })。加入(' '); ｝ console.log(titleCase(“我是一个小茶壶”));

在ECMAScript 6中，使用箭头函数的一行回答:

const captialize = words => words.split(' ').map( w =>  w.substring(0,1).toUpperCase()+ w.substring(1)).join(' ')

我认为这条路会快一些;因为它不会拆分字符串并重新连接;只是用正则表达式。

var str = text.toLowerCase().replace(/(^\w{1})|(\s{1}\w{1})/g, match => match.toUpperCase());

解释:

(^\w{1}):匹配字符串的第一个字符 |:或者 (\s{1}\w{1}):匹配一个空格后面的一个字符 G:全部匹配 match => match. touppercase (): replace with can take function, so;将匹配替换为大写匹配

TypeScript肥箭头FTW

export const formatTitleCase = (string: string) =>
    string
        .toLowerCase()
        .split(" ")
        .map((word) => word.charAt(0).toUpperCase() + word.substring(1))
        .join(" ");

function titleCase(str) { //First of all, lets make all the characters lower case let lowerCaseString = ""; for (let i = 0; i < str.length; i++) { lowerCaseString = lowerCaseString + str[i].toLowerCase(); } //Now lets make the first character in the string and the character after the empty character upper case and leave therest as it is let i = 0; let upperCaseString = ""; while (i < lowerCaseString.length) { if (i == 0) { upperCaseString = upperCaseString + lowerCaseString[i].toUpperCase(); } else if (lowerCaseString[i - 1] == " ") { upperCaseString = upperCaseString + lowerCaseString[i].toUpperCase(); } else { upperCaseString = upperCaseString + lowerCaseString[i]; } i = i + 1; } console.log(upperCaseString); return upperCaseString; } titleCase("hello woRLD");