从索引为 1 到 5 Javascript 的数组中返回项目

Question

我如何 console.log 当前数组中索引 1 到 5 的项目？使用循环let cars = ["AUDI","BMW","LEXUS","VOLKSWAGEN","FERRARY","PORSCHE"]const mappedCars=cars.map((item, i) => {    console.log("The current index is: " + i);    console.log("The current element is: " + item);    console.log("\n");    return item; //equivalent to list[index]});console.log(mappedCars);

Answer 1

使用 for 循环：

let cars = ["AUDI","BMW","LEXUS","VOLKSWAGEN","FERRARY","PORSCHE"]

for(i = 1; i<cars.length; i++){

    console.log("The current index is: " + i);

    console.log("The current element is: " + cars[i]);

    console.log("\n");

};

Answer 2

for loop您可以定义初始条件以及循环终止条件。

for ([initialExpression]; [condition]; [incrementExpression])

 statement

let cars = ["AUDI","BMW","LEXUS","VOLKSWAGEN","FERRARY","PORSCHE"]

const updated = [];

for (let i=1; i<=5; i++) {

        updated.push(cars[i]);

}

console.log(updated);

Answer 3

要在索引 1 到 5（包括） 的循环中执行此操作：

let cars = ["AUDI","BMW","LEXUS","VOLKSWAGEN","FERRARY","PORSCHE"]

const filteredCars = [];

for (let i=1; i<=5; i++) {

        filteredCars.push(cars[i]);

}

console.log(filteredCars);

如果没有循环，您也可以使用filter()or slice()。参见示例filter()：

let cars = ["AUDI","BMW","LEXUS","VOLKSWAGEN","FERRARY","PORSCHE"]

const filteredCars=cars.filter((item, i) => i>=1 && i<=5);

console.log(filteredCars);