SOURCE

let arr = [8,1,4,6,2,7,3,5]
function app (){
    // 比较八个数,外层循环 n-1=7(趟)
    for(let i = 0 ;i < arr.length-1; i++){
        // 内层循环 j与j+1比较 j+1最大值为7 j的取值0~6 7趟
        for(let j = 0; j < arr.length-i-1; j++){
            console.log(i,j,j+1)
            if(arr[j]>arr[j+1]){
                let temp;
                temp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = temp;
            }
        }
    }
    console.log(arr)
}
app()