index()+++js

array.index(element);

let fruits = ['apple', 'banana', 'cherry'];

// 查找 'banana' 的索引
let bananaIndex = fruits.index('banana');
console.log(bananaIndex); // 输出: 1

// 查找不存在的元素 'grape'
let grapeIndex = fruits.index('grape');
console.log(grapeIndex); // 输出: -1

let index = fruits.index('grape');
if (index !== -1) {
    console.log('Element found at index:', index);
} else {
    console.log('Element not found');
}

function findAllIndexes(arr, value) {
    let indexes = [];
    for (let i = 0; i < arr.length; i++) {
        if (arr[i] === value) {
            indexes.push(i);
        }
    }
    return indexes;
}

let indexesOfBanana = findAllIndexes(fruits, 'banana');
console.log(indexesOfBanana); // 输出: [1]