JavaScript Code and Result

let array = new Array(10);
for (let i = 0; i < 7; i++) {
    array[i] = i + 1;
}
let beforeInsert = array.slice();
console.log("插入前数组：", beforeInsert);
for (let i = 6; i >= 2; i--) {
    array[i + 1] = array[i];
}
array[2] = 8;
let afterInsert = array.slice();
console.log("插入后数组：", afterInsert);
for (let j = 0; j < afterInsert.length; j++) {
    console.log(`位置 ${j} 的值为:`, afterInsert[j]);
}
let indexOfSeven = -1;
for (let k = 0; k < afterInsert.length; k++) {
    if (afterInsert[k] === 7) {
        indexOfSeven = k;
        break;
    }
}
console.log("值为7的元素的位置序号为:", indexOfSeven);