JS 30 challenge - 06 心得

Demo & Github

DEMO

Regex

Regex 全名 Regular Expression (正規表達式)

正規表達式非常複雜，也是我目前還不熟悉的一塊，昨天有發現一個學習平台，決定有空時好好了解一下。

學習平台：RegexLearn 參閱：Regular expressions

function findMatches(wordToMatch, cities) {
	return cities.filter((place) => {
		// here we need to figure out if the city or state matches what was searched
		const regex = new RegExp(wordToMatch, "gi");
		return place.city.match(regex) || place.state.match(regex);
	});
}

這裡const regex = new RegExp(wordToMatch, "gi")是要讓使用者不管輸入大小寫都能找到相對應的城市與州。

function numberWithCommas(x) {
	return x.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}

以每三個 0 為單位劃出逗號，例如 12345678 => 12,345,678