JavaScript的replace方法怎么替换字符串？支持正则吗？

const originalString = "Hello world, hello JavaScript.";
const newString = originalString.replace("hello", "Hi");
console.log(newString); // 输出: "Hello world, Hi JavaScript."
// 注意，这里只替换了第一个 "hello"

const originalString = "Hello world, hello JavaScript.";
// 使用正则表达式 /hello/g，g 表示全局匹配
const newStringGlobal = originalString.replace(/hello/g, "Hi");
console.log(newStringGlobal); // 输出: "Hi world, Hi JavaScript."

const sentence = "The quick brown fox jumps over the lazy dog.";
// 将所有单词的首字母大写
const capitalizedSentence = sentence.replace(/\b\w/g, (match) => {
  return match.toUpperCase();
});
console.log(capitalizedSentence); // 输出: "The Quick Brown Fox Jumps Over The Lazy Dog."

// 替换数字，并进行计算
const priceText = "The price is $100 and tax is $10.";
const totalText = priceText.replace(/\$(\d+)/g, (match, p1) => {
  const value = parseInt(p1, 10);
  return `€${(value * 1.1).toFixed(2)}`; // 假设汇率是1.1，并保留两位小数
});
console.log(totalText); // 输出: "The price is €110.00 and tax is €11.00."

const text = "apple, orange, apple, banana, apple";
// 如果你这样写：
const singleReplace = text.replace("apple", "grape");
console.log(singleReplace); // 输出: "grape, orange, apple, banana, apple"
// 只有第一个 "apple" 变成了 "grape"。

// 但如果你想要全部替换，就必须用正则，并加上 'g' 旗标：
const globalReplace = text.replace(/apple/g, "grape");
console.log(globalReplace); // 输出: "grape, orange, grape, banana, grape"
// 这才是我们通常期望的“全部替换”。

const codeSnippet = "JavaScript is cool. javascript is fun.";
const replacedSnippet = codeSnippet.replace(/javascript/gi, "JS");
console.log(replacedSnippet); // 输出: "JS is cool. JS is fun."
// `gi` 组合意味着全局且不区分大小写地匹配。

const mathText = "The sum of 5 and 3 is (5+3). The product of 2 and 4 is (2*4).";
const calculatedText = mathText.replace(/\((\d+)([+\-*\/])(\d+)\)/g, (match, num1, operator, num2) => {
  const n1 = parseInt(num1, 10);
  const n2 = parseInt(num2, 10);
  let result;
  switch (operator) {
    case '+': result = n1 + n2; break;
    case '-': result = n1 - n2; break;
    case '*': result = n1 * n2; break;
    case '/': result = n1 / n2; break;
    default: return match; // 如果操作符不在预期范围内，返回原匹配
  }
  return result.toString();
});
console.log(calculatedText); // 输出: "The sum of 5 and 3 is 8. The product of 2 and 4 is 8."

const dateString = "2023-10-26";
const formattedDate = dateString.replace(/(\d{4})-(\d{2})-(\d{2})/, (match, year, month, day) => {
  return `${month}/${day}/${year}`;
});
console.log(formattedDate); // 输出: "10/26/2023"

const message = "Hello world, world is beautiful.";
// 使用 replaceAll 替换所有 "world"
const newMessage = message.replaceAll("world", "everyone");
console.log(newMessage); // 输出: "Hello everyone, everyone is beautiful."

// 记住，replaceAll 也可以接受正则表达式，但必须带 'g' 旗标，否则会报错。
// const errorExample = message.replaceAll(/world/, "everyone"); // 这样会报错

const sentence = "I love coding, coding is fun.";
// 先按 "coding" 分割，得到一个数组
const parts = sentence.split("coding"); // ["I love ", ", ", " is fun."]
// 然后在分割的每个部分之间插入新的内容
const newSentence = parts.join("programming");
console.log(newSentence); // 输出: "I love programming, programming is fun."

const data = "USER:JohnDoe;ID:12345;";
// 假设我们只想把 ID 改成 67890，并且知道 ID 后面跟着的是分号
const startIndex = data.indexOf("ID:") + "ID:".length;
const endIndex = data.indexOf(";", startIndex);

if (startIndex !== -1 && endIndex !== -1) {
  const newData = data.substring(0, startIndex) + "67890" + data.substring(endIndex);
  console.log(newData); // 输出: "USER: