是否有一个简单的方法来转换字符串标题大小写?例如,约翰·史密斯变成了约翰·史密斯。我不是在寻找像John Resig的解决方案那样复杂的东西,只是(希望)一些一两行代码。
当前回答
如果你需要一个语法正确的答案:
这个答案考虑了介词,如“of”,“from”,… 输出将生成您希望在论文中看到的编辑风格的标题。
toTitleCase函数
考虑此处列出的语法规则的函数。 该函数还合并空格和删除特殊字符(根据需要修改regex)
const toTitleCase = (str) => {
const articles = ['a', 'an', 'the'];
const conjunctions = ['for', 'and', 'nor', 'but', 'or', 'yet', 'so'];
const prepositions = [
'with', 'at', 'from', 'into','upon', 'of', 'to', 'in', 'for',
'on', 'by', 'like', 'over', 'plus', 'but', 'up', 'down', 'off', 'near'
];
// The list of spacial characters can be tweaked here
const replaceCharsWithSpace = (str) => str.replace(/[^0-9a-z&/\\]/gi, ' ').replace(/(\s\s+)/gi, ' ');
const capitalizeFirstLetter = (str) => str.charAt(0).toUpperCase() + str.substr(1);
const normalizeStr = (str) => str.toLowerCase().trim();
const shouldCapitalize = (word, fullWordList, posWithinStr) => {
if ((posWithinStr == 0) || (posWithinStr == fullWordList.length - 1)) {
return true;
}
return !(articles.includes(word) || conjunctions.includes(word) || prepositions.includes(word));
}
str = replaceCharsWithSpace(str);
str = normalizeStr(str);
let words = str.split(' ');
if (words.length <= 2) { // Strings less than 3 words long should always have first words capitalized
words = words.map(w => capitalizeFirstLetter(w));
}
else {
for (let i = 0; i < words.length; i++) {
words[i] = (shouldCapitalize(words[i], words, i) ? capitalizeFirstLetter(words[i], words, i) : words[i]);
}
}
return words.join(' ');
}
确保正确性的单元测试
import { expect } from 'chai';
import { toTitleCase } from '../../src/lib/stringHelper';
describe('toTitleCase', () => {
it('Capitalizes first letter of each word irrespective of articles, conjunctions or prepositions if string is no greater than two words long', function(){
expect(toTitleCase('the dog')).to.equal('The Dog'); // Capitalize articles when only two words long
expect(toTitleCase('for all')).to.equal('For All'); // Capitalize conjunctions when only two words long
expect(toTitleCase('with cats')).to.equal('With Cats'); // Capitalize prepositions when only two words long
});
it('Always capitalize first and last words in a string irrespective of articles, conjunctions or prepositions', function(){
expect(toTitleCase('the beautiful dog')).to.equal('The Beautiful Dog');
expect(toTitleCase('for all the deadly ninjas, be it so')).to.equal('For All the Deadly Ninjas Be It So');
expect(toTitleCase('with cats and dogs we are near')).to.equal('With Cats and Dogs We Are Near');
});
it('Replace special characters with space', function(){
expect(toTitleCase('[wolves & lions]: be careful')).to.equal('Wolves & Lions Be Careful');
expect(toTitleCase('wolves & lions, be careful')).to.equal('Wolves & Lions Be Careful');
});
it('Trim whitespace at beginning and end', function(){
expect(toTitleCase(' mario & Luigi superstar saga ')).to.equal('Mario & Luigi Superstar Saga');
});
it('articles, conjunctions and prepositions should not be capitalized in strings of 3+ words', function(){
expect(toTitleCase('The wolf and the lion: a tale of two like animals')).to.equal('The Wolf and the Lion a Tale of Two like Animals');
expect(toTitleCase('the three Musketeers And plus ')).to.equal('The Three Musketeers and Plus');
});
});
请注意,我从提供的字符串中删除了相当多的特殊字符。您将需要调整正则表达式以满足项目的需求。
其他回答
使用/\S+/g支持变音符:
function toTitleCase(str) replace str.replace(/\S+/g, str => str.charAt(0). toupbelise (str.substr, 1); 的 控制台(toTitleCase(“一个城市叫orebro”);-一个叫Orebro的城市
然而:“阳光(黄色)”⇒“阳光(黄色)”
没有正则表达式,没有循环,没有分割,没有子字符串:
String.prototype.toTitleCase = function(){返回this.valueOf().toLowerCase().replace(this.valueOf()[0], this.valueOf()[0].toUpperCase());} console.log(“莱拉”.toTitleCase ());
有一些很好的答案,但是,许多人使用正则表达式来查找单词,但是,由于某种原因,没有人使用正则表达式来替换第一个字符。为了解释,我将提供一个较长的解决方案和一个较短的解决方案。
长期解决方案(更具解释性)。通过使用正则表达式[^\s_\-/]*,我们可以找到句子中的每一个单词。随后,我们可以使用正则表达式。与单词中的第一个字符匹配。使用正则表达式版本的replace来替换这两个函数,我们可以像这样更改解决方案:
function toUpperCase(str){返回str.toUpperCase();} 函数capitalizeWord(word){返回word.replace(/。/,包含);} 函数大写(句子){返回句子。tolowercase()。替换(/ [/ ^ \ s_ \] * / g, capitalizeWord);} console.log(大写(“hello world”));//输出:Hello World
对于做同样事情的单个函数,我们将replace调用嵌套如下:
函数大写(句子){ 返回sentence.toLowerCase()。替换(/[^\s_\-/]*/g, function (word) { 返回word.replace(/。/,函数(ch){返回ch. touppercase ();}); }); } console.log(大写(“hello world”));//输出:Hello World
我认为最简单的是使用css。
function format_str(str) {
str = str.toLowerCase();
return '<span style="text-transform: capitalize">'+ str +'</span>';
}
这里有一个非常简单而简洁的ES6函数来做到这一点:
const titleCase = (str) => {
return str.replace(/\w\S*/g, (t) => { return t.charAt(0).toUpperCase() + t.substr(1).toLowerCase() });
}
export default titleCase;
工作良好,包括在一个实用程序文件夹,并使用如下:
import titleCase from './utilities/titleCase.js';
const string = 'my title & string';
console.log(titleCase(string)); //-> 'My Title & String'