替换空格（剑指Offer 05）

题目

请实现一个函数，把字符串 s 中的每个空格替换成"%20"。

示例

输入：s = "We are happy." 输出："We%20are%20happy."

限制

• 0 <= s 的长度 <= 10000

算法

replaceAll()

export const replaceSpace = (s) => {
	return s.replaceAll(" ", "%20");
};

正则

export const replaceSpace = (s) => {
	return s.replaceAll(/ /g, "%20");
};

split() + join()

export const replaceSpace = (s) => {
	return s.split(" ").join("%20");
};

数组

export const replaceSpace = (s) => {
	const arr = [];
	for (let i = 0; i < s.length; i++) {
		if (s[i] === " ") arr.push("%20");
		else arr.push(s[i]);
	}
	return arr.join("");
};

指针

export const replaceSpace = (s) => {
	let replaceString = "";
	let i = 0;
	while (i < s.length) {
		replaceString += s[i] === " " ? "%20" : s[i];
		i++;
	}
	return replaceString;
};