js截断数组的几种方法

 {
            // 通过length获取前面几项
            let arr = [1,2,3,4]
            arr.length = 2 
            console.log(arr); // [1,2]
        }

        {
            // 通过splice获取前面几项
            let arr = [1,2,3,4]
            console.log(arr.splice(0,2));// [1,2]
        }

        {
            // 通过splice获取后面几项
            let arr = [1,2,3,4]
            console.log(arr.splice(-2));// [3,4]
        }

        {
            // 通过解构赋值获取后面几项
            let arr = [1,2,3,4]
            let [a,b,...v] = arr
            console.log([...v]); // [3,4]
        }