配列使用経験例について

配列使用例

は、削除配列の複数の要素

を指定する.

配列文字列-回転数

配列と文字列-相互変換

は、idに基づいてツリー構造データ中の完全経路

を取得する.
配列から削除する複数の要素を指定します.
例:[1,2,3,4,5,6,7]配列から2,4,5,7の4つの要素を削除します.

let arr1 = [ 1,2,3,4,5,6,7];
let arr2 = [2,4,5,7]; 
for(let obj of arr2){
	arr1 = arr1.filter(item => item !== obj);
}
console.log(arr1);
//   ：[1,3,6]

配列文字列-回転数

//    
let arr = ["2","4","6","8","10","13"]
let arr2 = arr.map(item => {
	return +item
});
console.log(arr2)
// [2, 4, 6, 8, 10, 13]

//    
let arr2 = ["2","4","6","8","10","13"].map(Number);
console.log(arr2)
// [2, 4, 6, 8, 10, 13]

配列と文字列→相互変換

配列変換文字列

//  ‘-’         
let str = [0,1,2,3,4].join('-');
console.log(str);
// 0-1-2-3-4

文字列変換配列

//    （,）    ，        
let str = "hello,wworld,hi"
let arr = str.split(',');
console.log(arr);
// ["hello", "wworld", "hi"]

IDに基づいてツリー構造データのフルパスを取得します.

//   
let arr = [{
    "id": 1,
    "name": "    ",
    "level": 1,
    "fullPath": "1",
    "parentId": 0,
    "children": [{
        "id": 2,
        "name": "    ",
        "level": 2,
        "fullPath": "1-2",
        "parentId": 1,
        "children": [{
            "id": 3,
            "name": " ",
            "level": 3,
            "fullPath": "1-2-3",
            "parentId": 2
        }, {
            "id": 26,
            "name": "  ",
            "level": 3,
            "fullPath": "1-2-26",
            "parentId": 2
        }, {
            "id": 27,
            "name": "  ",
            "level": 3,
            "fullPath": "1-2-27",
            "parentId": 2
        }, {
            "id": 28,
            "name": "  ",
            "level": 3,
            "fullPath": "1-2-28",
            "parentId": 2
        }, {
            "id": 29,
            "name": "   ",
            "level": 3,
            "fullPath": "1-2-29",
            "parentId": 2
        }, {
            "id": 38,
            "name": "  ",
            "level": 3,
            "fullPath": "1-2-38",
            "parentId": 2
        }]
    }, {
        "id": 10,
        "name": "    ",
        "level": 2,
        "fullPath": "1-10",
        "parentId": 1,
        "children": [{
            "id": 11,
            "name": "   ",
            "level": 3,
            "fullPath": "1-10-11",
            "parentId": 10
        }, {
            "id": 14,
            "name": "    ",
            "level": 3,
            "fullPath": "1-10-14",
            "parentId": 10
        }, {
            "id": 17,
            "name": "  ",
            "level": 3,
            "fullPath": "1-10-17",
            "parentId": 10
        }, {
            "id": 20,
            "name": "   ",
            "level": 3,
            "fullPath": "1-10-20",
            "parentId": 10
        }, {
            "id": 23,
            "name": "  ",
            "level": 3,
            "fullPath": "1-10-23",
            "parentId": 10
        }]
    }]
}]