上面的答案对我来说都不完美，所以我不得不带着自己的自行车:

function camelCaseToTitle(camelCase) {
    if (!camelCase) {
        return '';
    }

    var pascalCase = camelCase.charAt(0).toUpperCase() + camelCase.substr(1);
    return pascalCase
        .replace(/([a-z])([A-Z])/g, '$1 $2')
        .replace(/([A-Z])([A-Z][a-z])/g, '$1 $2')
        .replace(/([a-z])([0-9])/gi, '$1 $2')
        .replace(/([0-9])([a-z])/gi, '$1 $2');
}

测试用例:

null => ''
'' => ''
'simpleString' => 'Simple String'
'stringWithABBREVIATIONInside => 'String With ABBREVIATION Inside'
'stringWithNumber123' => 'String With Number 123'
'complexExampleWith123ABBR890Etc' => 'Complex Example With 123 ABBR 890 Etc'

你可以使用这样的函数:

function fixStr(str) {
    var out = str.replace(/^\s*/, "");  // strip leading spaces
    out = out.replace(/^[a-z]|[^\s][A-Z]/g, function(str, offset) {
        if (offset == 0) {
            return(str.toUpperCase());
        } else {
            return(str.substr(0,1) + " " + str.substr(1).toUpperCase());
        }
    });
    return(out);
}

"hello World" ==> "Hello World"
"HelloWorld" ==> "Hello World"
"FunInTheSun" ==? "Fun In The Sun"

带有一堆测试字符串的代码:http://jsfiddle.net/jfriend00/FWLuV/。

保留前导空格的替代版本:http://jsfiddle.net/jfriend00/Uy2ac/。

我认为这可以用reg exp /([a-z]|[a-z] +)([a-z])/g和替换“$1 $2”来完成。

我爱美国的毒品

此解决方案也适用于不在[A-Z]范围内的其他Unicode字符。例如:Ä， Ö， Å。

let camelCaseToTitleCase = (s) => (
  s.split("").reduce(
    (acc, letter, i) => (
      i === 0 || console.log(acc, letter, i)
        ? [...acc, letter.toUpperCase()] 
        : letter === letter.toUpperCase()
        ? [...acc, " ", letter]
        : [...acc, letter] 
    ), []
  ).join("")
)

const myString = "ArchipelagoOfÅland"
camelCaseToTitleCase(myString)

我也遇到过类似的问题，我是这样处理的:

stringValue.replace(/([A-Z]+)*([A-Z][a-z])/g, "$1 $2")

对于更健壮的解决方案:

stringValue.replace(/([A-Z]+)/g, " $1").replace(/([A-Z][a-z])/g, " $1")

http://jsfiddle.net/PeYYQ/

输入:

 helloThere 
 HelloThere 
 ILoveTheUSA
 iLoveTheUSA

输出:

 hello There 
 Hello There 
 I Love The USA
 i Love The USA

我发现用于测试驼峰式大小写到标题式大小写函数的最佳字符串是这个荒谬的示例，它测试了许多边缘用例。据我所知，之前发布的函数都没有正确地处理这个:

__ToGetYourGEDInTimeASongAboutThe26ABCsIsOfTheEssenceButAPersonalIDCardForUser_456InRoom26AContainingABC26TimesIsNotAsEasyAs123ForC3POOrR2D2Or2R2D

这应该转换为:

一首关于26个ABC的歌曲是很重要的，但是对于26A房间的456号用户来说，一张包含ABC 26倍的个人身份证并不像C3PO或R2D2或2R2D的123那么容易

如果您只想要一个简单的函数来处理类似上面的情况(并且比以前的答案更多的情况)，这里是我写的一个。这段代码不是特别优雅或快速，但它简单、可理解且有效。

下面的代码片段包含一个在线可运行的示例:

var mystrings = [ "__ToGetYourGEDInTimeASongAboutThe26ABCsIsOfTheEssenceButAPersonalIDCardForUser_456InRoom26AContainingABC26TimesIsNotAsEasyAs123ForC3POOrR2D2Or2R2D", "helloThere", "HelloThere", "ILoveTheUSA", "iLoveTheUSA", "DBHostCountry", "SetSlot123ToInput456", "ILoveTheUSANetworkInTheUSA", "Limit_IOC_Duration", "_This_is_a_Test_of_Network123_in_12__days_", "ASongAboutTheABCsIsFunToSing", "CFDs", "DBSettings", "IWouldLove1Apple", "Employee22IsCool", "SubIDIn", "ConfigureABCsImmediately", "UseMainNameOnBehalfOfSubNameInOrders" ]; // Take a single camel case string and convert it to a string of separate words (with spaces) at the camel-case boundaries. // // E.g.: // __ToGetYourGEDInTimeASongAboutThe26ABCsIsOfTheEssenceButAPersonalIDCardForUser_456InRoom26AContainingABC26TimesIsNotAsEasyAs123ForC3POOrR2D2Or2R2D // --> To Get Your GED In Time A Song About The 26 ABCs Is Of The Essence But A Personal ID Card For User 456 In Room 26A Containing ABC 26 Times Is Not As Easy As 123 For C3PO Or R2D2 Or 2R2D // helloThere --> Hello There // HelloThere --> Hello There // ILoveTheUSA --> I Love The USA // iLoveTheUSA --> I Love The USA // DBHostCountry --> DB Host Country // SetSlot123ToInput456 --> Set Slot 123 To Input 456 // ILoveTheUSANetworkInTheUSA --> I Love The USA Network In The USA // Limit_IOC_Duration --> Limit IOC Duration // This_is_a_Test_of_Network123_in_12_days --> This Is A Test Of Network 123 In 12 Days // ASongAboutTheABCsIsFunToSing --> A Song About The ABCs Is Fun To Sing // CFDs --> CFDs // DBSettings --> DB Settings // IWouldLove1Apple --> I Would Love 1 Apple // Employee22IsCool --> Employee 22 Is Cool // SubIDIn --> Sub ID In // ConfigureCFDsImmediately --> Configure CFDs Immediately // UseTakerLoginForOnBehalfOfSubIDInOrders --> Use Taker Login For On Behalf Of Sub ID In Orders // function camelCaseToTitleCase(in_camelCaseString) { var result = in_camelCaseString // "__ToGetYourGEDInTimeASongAboutThe26ABCsIsOfTheEssenceButAPersonalIDCardForUser_456InRoom26AContainingABC26TimesIsNotAsEasyAs123ForC3POOrR2D2Or2R2D" .replace(/(_)+/g, ' ') // " ToGetYourGEDInTimeASongAboutThe26ABCsIsOfTheEssenceButAPersonalIDCardForUser 456InRoom26AContainingABC26TimesIsNotAsEasyAs123ForC3POOrR2D2Or2R2D" .replace(/([a-z])([A-Z][a-z])/g, "$1 $2") // " To Get YourGEDIn TimeASong About The26ABCs IsOf The Essence ButAPersonalIDCard For User456In Room26AContainingABC26Times IsNot AsEasy As123ForC3POOrR2D2Or2R2D" .replace(/([A-Z][a-z])([A-Z])/g, "$1 $2") // " To Get YourGEDIn TimeASong About The26ABCs Is Of The Essence ButAPersonalIDCard For User456In Room26AContainingABC26Times Is Not As Easy As123ForC3POOr R2D2Or2R2D" .replace(/([a-z])([A-Z]+[a-z])/g, "$1 $2") // " To Get Your GEDIn Time ASong About The26ABCs Is Of The Essence But APersonal IDCard For User456In Room26AContainingABC26Times Is Not As Easy As123ForC3POOr R2D2Or2R2D" .replace(/([A-Z]+)([A-Z][a-z][a-z])/g, "$1 $2") // " To Get Your GEDIn Time A Song About The26ABCs Is Of The Essence But A Personal ID Card For User456In Room26A ContainingABC26Times Is Not As Easy As123ForC3POOr R2D2Or2R2D" .replace(/([a-z]+)([A-Z0-9]+)/g, "$1 $2") // " To Get Your GEDIn Time A Song About The 26ABCs Is Of The Essence But A Personal ID Card For User 456In Room 26A Containing ABC26Times Is Not As Easy As 123For C3POOr R2D2Or 2R2D" // Note: the next regex includes a special case to exclude plurals of acronyms, e.g. "ABCs" .replace(/([A-Z]+)([A-Z][a-rt-z][a-z]*)/g, "$1 $2") // " To Get Your GED In Time A Song About The 26ABCs Is Of The Essence But A Personal ID Card For User 456In Room 26A Containing ABC26Times Is Not As Easy As 123For C3PO Or R2D2Or 2R2D" .replace(/([0-9])([A-Z][a-z]+)/g, "$1 $2") // " To Get Your GED In Time A Song About The 26ABCs Is Of The Essence But A Personal ID Card For User 456In Room 26A Containing ABC 26Times Is Not As Easy As 123For C3PO Or R2D2Or 2R2D" // Note: the next two regexes use {2,} instead of + to add space on phrases like Room26A and 26ABCs but not on phrases like R2D2 and C3PO" .replace(/([A-Z]{2,})([0-9]{2,})/g, "$1 $2") // " To Get Your GED In Time A Song About The 26ABCs Is Of The Essence But A Personal ID Card For User 456 In Room 26A Containing ABC 26 Times Is Not As Easy As 123 For C3PO Or R2D2 Or 2R2D" .replace(/([0-9]{2,})([A-Z]{2,})/g, "$1 $2") // " To Get Your GED In Time A Song About The 26 ABCs Is Of The Essence But A Personal ID Card For User 456 In Room 26A Containing ABC 26 Times Is Not As Easy As 123 For C3PO Or R2D2 Or 2R2D" .trim() // "To Get Your GED In Time A Song About The 26 ABCs Is Of The Essence But A Personal ID Card For User 456 In Room 26A Containing ABC 26 Times Is Not As Easy As 123 For C3PO Or R2D2 Or 2R2D" ; // capitalize the first letter return result.charAt(0).toUpperCase() + result.slice(1); } for (var i = 0; i < mystrings.length; i++) { jQuery(document.body).append("<br />\""); jQuery(document.body).append(camelCaseToTitleCase(mystrings[i])); jQuery(document.body).append("\"<br>(was: \""); jQuery(document.body).append(mystrings[i]); jQuery(document.body).append("\") <br />"); } <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.2.3/jquery.min.js"></script>