我如何转换字符串既像'helloThere'或'helloThere'到'HelloThere'在JavaScript?
当前回答
或者使用lodash:
lodash.startCase(str);
例子:
_.startCase('helloThere');
// ➜ 'Hello There'
Lodash是一个很好的库，可以为许多日常的js任务提供快捷方式。还有许多其他类似的字符串操作函数，如camelCase, kebabCase等。
其他回答
我没有尝试每个人的答案，但我修补过的几个解决方案并不能满足我所有的要求。
我想出了一个办法…
export const jsObjToCSSString = (o={}) =>
Object.keys(o)
.map(key => ({ key, value: o[key] }))
.map(({key, value}) =>
({
key: key.replace( /([A-Z])/g, "-$1").toLowerCase(),
value
})
)
.reduce(
(css, {key, value}) =>
`${css} ${key}: ${value}; `.trim(),
'')
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 $2") // " To Get Your GED In Time A Song About The 26 ABCs Is Of The Essence But A Personal ID Card For User 456 In Room 26A Containing ABC 26 Times Is Not As Easy As 123 For C3PO Or R2D2 Or 2R2D" .trim() // "To Get Your GED In Time A Song About The 26 ABCs Is Of The Essence But A Personal ID Card For User 456 In Room 26A Containing ABC 26 Times Is Not As Easy As 123 For C3PO Or R2D2 Or 2R2D" ; // capitalize the first letter return result.charAt(0).toUpperCase() + result.slice(1); } for (var i = 0; i < mystrings.length; i++) { jQuery(document.body).append("<br />\""); jQuery(document.body).append(camelCaseToTitleCase(mystrings[i])); jQuery(document.body).append("\"<br>(was: \""); jQuery(document.body).append(mystrings[i]); jQuery(document.body).append("\") <br />"); } <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.2.3/jquery.min.js"></script>
另一个基于RegEx的解决方案。
respace(str) {
const regex = /([A-Z])(?=[A-Z][a-z])|([a-z])(?=[A-Z])/g;
return str.replace(regex, '$& ');
}
解释
上面的正则表达式由两个相似的部分组成，由OR运算符分开。前半部分:
([A-Z]) -匹配大写字母… (?=[a-z] [a-z]) -后面跟着一个大写字母和小写字母的序列。
当应用于序列FOo时，它有效地匹配它的F字母。
或者第二种情况:
([a-z]) -匹配小写字母… (?=[A-Z]) -后面跟着一个大写字母。
当应用于序列barFoo时，它有效地匹配了它的r字母。
当找到所有替换候选时，最后要做的事情是用相同的字母替换它们，但要使用额外的空格字符。为此，我们可以使用'$& '作为替换，它将解析为一个匹配的子字符串，后面跟着一个空格字符。
例子
const regex = /([A-Z])(?=[A-Z][a-z])|([a-z])(?=[A-Z])/g
const testWords = ['ACoolExample', 'fooBar', 'INAndOUT', 'QWERTY', 'fooBBar']
testWords.map(w => w.replace(regex, '$& '))
->(5) ["A Cool Example", "foo Bar", "IN And OUT", "QWERTY", "foo B Bar"]
好吧，我在这个游戏上晚了几年，但我有一个类似的问题，我想为每一个可能的输入提供一个替换的解决方案。我必须把大部分功劳归功于本帖中的@ZenMaster和本帖中的@Benjamin Udink ten Cate。 代码如下:
var camelEdges = /([A-Z](?=[A-Z][a-z])|[^A-Z](?=[A-Z])|[a-zA-Z](?=[^a-zA-Z]))/g;
var textArray = ["lowercase",
"Class",
"MyClass",
"HTML",
"PDFLoader",
"AString",
"SimpleXMLParser",
"GL11Version",
"99Bottles",
"May5",
"BFG9000"];
var text;
var resultArray = [];
for (var i = 0; i < textArray.length; i++){
text = textArray[i];
text = text.replace(camelEdges,'$1 ');
text = text.charAt(0).toUpperCase() + text.slice(1);
resultArray.push(text);
}
它有三个子句，都使用了lookahead来防止正则表达式引擎消耗太多字符:
[a-z] (?=[a-z] [a-z])查找一个大写字母，后面跟着一个大写字母，然后是小写字母。这将终结像USA这样的缩写词。 [^ a - z](?=[a - z])查找一个非大写字母后跟一个大写字母。这结束了像myWord这样的单词和像99Bottles这样的符号。 [a- za -z](?=[^a- za -z])查找一个字母后面跟着一个非字母。它以像BFG9000这样的符号前的单词结尾。
这个问题在我的搜索结果的顶部，所以希望我可以为其他人节省一些时间!
这个对我有用看看这个
CamelcaseToWord(“名字”);//返回我的名字
function CamelcaseToWord(string){
return string.replace(/([A-Z]+)/g, " $1").replace(/([A-Z][a-z])/g, " $1");
}
