每个点 (.) 和字符串开头后的单词大写

Question

如何在字符串开头和点（.）符号之后将每个单词大写？

我对google和stackoverflow进行了研究，下面是我实现的代码，但这只会将字符串的开头大写。示例如下；

var str = 'this is a text. hello world!';
str = str.replace(/^(.)/g, str[0].toUpperCase());
document.write(str);

我想要的字符串是This is a text. Hello world!.

我尝试使用CSS，text-transform: capitalize;但这会导致每个单词都大写。

Answer 1

我使用这样的函数，它带有一个可选的第二个参数，该参数最初会将整个字符串转换为小写。原因是有时你有一系列的Title Case Items. That You Wish要变成一系列的Title case items. That you wish有作为句子大小写。

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function sentenceCase(input, lowercaseBefore) {\n    input = ( input === undefined || input === null ) ? \'\' : input;\n    if (lowercaseBefore) { input = input.toLowerCase(); }\n    return input.toString().replace( /(^|\\. *)([a-z])/g, function(match, separator, char) {\n        return separator + char.toUpperCase();\n    });\n}\n

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正则表达式的工作原理如下

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1st Capturing Group (^|\\. *)\n    1st Alternative ^\n        ^ asserts position at start of the string\n    2nd Alternative \\. *\n        \\. matches the character `.` literally (case sensitive)\n         * matches the character ` ` literally (case sensitive)\n        * Quantifier \xe2\x80\x94 Matches between zero and unlimited times, as many times as possible, giving back as needed (greedy)\n2nd Capturing Group ([a-z])\n    Match a single character present in the list below [a-z]\n    a-z a single character in the range between a (ASCII 97) and z (ASCII 122) (case sensitive)\n

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您可以在示例中实现它，如下所示：

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var str = \'this is a text. hello world!\';\nstr = sentenceCase(str);\ndocument.write(str); // This is a text. Hello world!\n

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示例jsfiddle

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附言。将来，我发现regex101 是一个非常有用的工具，用于理解和测试 regex

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