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
健壮的函数式编程方式做标题大小写函数
Exaplin版本
function toTitleCase(input){
let output = input
.split(' ') // 'HOw aRe YOU' => ['HOw' 'aRe' 'YOU']
.map((letter) => {
let firstLetter = letter[0].toUpperCase() // H , a , Y => H , A , Y
let restLetters = letter.substring(1).toLowerCase() // Ow, Re, OU => ow, re, ou
return firstLetter + restLetters // conbine together
})
.join(' ') //['How' 'Are' 'You'] => 'How Are You'
return output
}
实现版本
function toTitleCase(input){
return input
.split(' ')
.map(i => i[0].toUpperCase() + i.substring(1).toLowerCase())
.join(' ')
}
toTitleCase('HoW ARe yoU') // reuturn 'How Are You'
其他回答
https://lodash.com/docs/4.17.11#capitalize
使用Lodash库!!更可靠的
_.capitalize('FRED'); => 'Fred'
一个使用lodash -的解决方案
import { words, lowerCase, capitalize, endsWith, padEnd } from 'lodash';
const titleCase = string =>
padEnd(
words(string, /[^ ]+/g)
.map(lowerCase)
.map(capitalize)
.join(' '),
string.length,
);
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。
ES-6 way to get title case of a word or entire line.
ex. input = 'hEllo' --> result = 'Hello'
ex. input = 'heLLo woRLd' --> result = 'Hello World'
const getTitleCase = (str) => {
if(str.toLowerCase().indexOf(' ') > 0) {
return str.toLowerCase().split(' ').map((word) => {
return word.replace(word[0], word[0].toUpperCase());
}).join(' ');
}
else {
return str.slice(0, 1).toUpperCase() + str.slice(1).toLowerCase();
}
}
与John Resig的解决方案一样功能齐全,但作为一行程序:(基于此github项目)
function toTitleCase(e){var t=/^(a|an|and|as|at|but|by|en|for|if|in|of|on|or|the|to|vs?\.?|via)$/i;return e.replace(/([^\W_]+[^\s-]*) */g,function(e,n,r,i){return r>0&&r+n.length!==i.length&&n.search(t)>-1&&i.charAt(r-2)!==":"&&i.charAt(r-1).search(/[^\s-]/)<0?e.toLowerCase():n.substr(1).search(/[A-Z]|\../)>-1?e:e.charAt(0).toUpperCase()+e.substr(1)})};
console.log( toTitleCase( "ignores mixed case words like iTunes, and allows AT&A and website.com/address etc..." ) );
推荐文章
- 我如何使用Jest模拟JavaScript的“窗口”对象?
- 我如何等待一个承诺完成之前返回一个函数的变量?
- 在JavaScript中根据键值查找和删除数组中的对象
- 使嵌套JavaScript对象平放/不平放的最快方法
- 如何以及为什么'a'['toUpperCase']()在JavaScript工作?
- 有Grunt生成index.html不同的设置
- 文档之间的区别。addEventListener和window。addEventListener?
- 如何检查动态附加的事件监听器是否存在?
- 如何写setTimeout与参数Coffeescript
- 将JavaScript字符串中的多个空格替换为单个空格
- JavaScript: override alert()
- 重置setTimeout
- 如何确保<select>表单字段被禁用时提交?
- jQuery有不聚焦的方法吗?
- 反应钩子-正确的方式清除超时和间隔