Capitalizes the first letter of a string.
Use array destructuring and String.prototype.toUpperCase()
to capitalize first letter, ...rest
to get array of characters after first letter and then Array.prototype.join('')
to make it a string again.
Omit the lowerRest
parameter to keep the rest of the string intact, or set it to true
to convert to lowercase.
代码片段
const capitalize = ([first, ...rest], lowerRest = false) =>
first.toUpperCase() + (lowerRest ? rest.join('').toLowerCase() : rest.join(''));
使用样例
capitalize('fooBar'); // 'FooBar'
capitalize('fooBar', true); // 'Foobar'