js replace 替换/

str.replace(regexp|substr, newSubstr|function)

let str = "Hello, World!";
let newStr = str.replace("World", "JavaScript");
console.log(newStr); // 输出: "Hello, JavaScript!"

let str = "apple, banana, apple pie";
let newStr = str.replace(/apple/g, "orange");
console.log(newStr); // 输出: "orange, banana, orange pie"

let str = "I have 3 apples and 2 bananas.";
let newStr = str.replace(/\d+/g, function(match) {
    return parseInt(match) * 2;
});
console.log(newStr); // 输出: "I have 6 apples and 4 bananas."