SOURCE

//消除一个数组里面重复的元素
let arr=[1,2,3,3,4,4,5,5,6,1,9,3,25,4];

function delRepeat(arr) {
    // let newArr = new Set(arr)
    // return Array.from(newArr)

    let newArr = []
    for(var i = 0; i < arr.length; i++){
        if(newArr.indexOf(arr[i]) === -1) newArr.push(arr[i])
    }

     console.log(newArr)
}

delRepeat(arr);