在 js 中循环遍历相同的 object

Question

{
    "uri": "https://www.fsa.go.jp/en/newsletter/index.html",
    "path": "D:\\SSN_INS\\JP--FSA--INS--NEWSLETTER\\",
    "pattern": "/.+/",
    "scope": "#main",
    "selector": "void",
    "extractors": [
        {
            "name": "TitleHtml",
            "query": {
                "scope": "title"
            }
        },
        {
            "name": "Title",
            "query": {
                "scope": "title"
            }
        }
    ],
    "tree": [
        {
            "type": "pseudo",
            "scope": ":scope .col-two_fp > div h2",
            "extractors": [
                {
                    "name": "Title",
                    "query": {
                        "scope": ":scope"
                    }
                },
                {
                    "name": "TitleHtml",
                    "query": {
                        "scope": ":scope"
                    }
                }
            ],
            "tree": [
                {
                    "type": "pseudo",
                    "scope": ":scope ~ h3",
                    "extractors": [
                        {
                            "name": "Title",
                            "query": {
                                "scope": ":scope",
                                "exclude": "span:has(a)"
                            }
                        },
                        {
                            "name": "TitleHtml",
                            "query": {
                                "scope": ":scope",
                                "exclude": "span:has(a)"
                            }
                        }
                    ],
                    "tree": [
                        {
                            "type": "pseudo",
                            "scope": ":scope ~ h4",
                            "extractors": [
                                {
                                    "name": "Title",
                                    "query": {
                                        "scope": ":scope",
                                        "exclude": "span:has(a)"
                                    }
                                },
                                {
                                    "name": "TitleHtml",
                                    "query": {
                                        "scope": ":scope",
                                        "exclude": "span:has(a)"
                                    }
                                }
                            ]

                        }
                    ]

                }
            ]
        }
    ]
}

This is an object has 'tree' for each and I need to get the length and loop through it

Answer 1

Assuming your object is stored in a variable $a , then $a['tree'] will give you the 'tree' array. You can use forEach to loop through it: $a['tree'].forEach() (no need to determine the length).

If you need the length , use $a['tree'].length .

Answer 2

May use recursion if expected tree length is not very large.

 var data = { "uri": "https://www.fsa.go.jp/en/newsletter/index.html", "path": "D:\\SSN_INS\\JP--FSA--INS--NEWSLETTER\\", "pattern": "/.+/", "scope": "#main", "selector": "void", "extractors": [ { "name": "TitleHtml", "query": { "scope": "title" } }, { "name": "Title", "query": { "scope": "title" } } ], "tree": [ { "type": "pseudo", "scope": ":scope.col-two_fp > div h2", "extractors": [ { "name": "Title", "query": { "scope": ":scope" } }, { "name": "TitleHtml", "query": { "scope": ":scope" } } ], "tree": [ { "type": "pseudo", "scope": ":scope ~ h3", "extractors": [ { "name": "Title", "query": { "scope": ":scope", "exclude": "span:has(a)" } }, { "name": "TitleHtml", "query": { "scope": ":scope", "exclude": "span:has(a)" } } ], "tree": [ { "type": "pseudo", "scope": ":scope ~ h4", "extractors": [ { "name": "Title", "query": { "scope": ":scope", "exclude": "span:has(a)" } }, { "name": "TitleHtml", "query": { "scope": ":scope", "exclude": "span:has(a)" } } ] } ] } ] } ] } function findObjectByLabel(node, key, childList) { if(;childList) childList = []. if(node;hasOwnProperty(key)) { node = node[key][0]. childList;push(node), return findObjectByLabel(node, key; childList); } return childList, } var childList = findObjectByLabel(data; "tree"); for(var i=0. i < childList;length. ++i) console;log(childList[i]);

Answer 3

You need a recursive dig function?

 function dig(obj, func){ let v; if(obj instanceof Array){ for(let i=0,l=obj.length; i<l; i++){ v = obj[i]; if(typeof v === 'object'){ dig(v, func); } else{ func(v, i); } } } else{ for(let i in obj){ v = obj[i]; if(typeof v === 'object'){ dig(v, func); } else{ func(v, i); } } } } const data = { "uri": "https://www.fsa.go.jp/en/newsletter/index.html", "path": "D:\\SSN_INS\\JP--FSA--INS--NEWSLETTER\\", "pattern": "/.+/", "scope": "#main", "selector": "void", "extractors": [ { "name": "TitleHtml", "query": { "scope": "title" } }, { "name": "Title", "query": { "scope": "title" } } ], "tree": [ { "type": "pseudo", "scope": ":scope.col-two_fp > div h2", "extractors": [ { "name": "Title", "query": { "scope": ":scope" } }, { "name": "TitleHtml", "query": { "scope": ":scope" } } ], "tree": [ { "type": "pseudo", "scope": ":scope ~ h3", "extractors": [ { "name": "Title", "query": { "scope": ":scope", "exclude": "span:has(a)" } }, { "name": "TitleHtml", "query": { "scope": ":scope", "exclude": "span:has(a)" } } ], "tree": [ { "type": "pseudo", "scope": ":scope ~ h4", "extractors": [ { "name": "Title", "query": { "scope": ":scope", "exclude": "span:has(a)" } }, { "name": "TitleHtml", "query": { "scope": ":scope", "exclude": "span:has(a)" } } ] } ] } ] } ] } dig(data, (v, i)=>{ console.log({key:i, value:v}); });

It's similar to array_walk_recursive in PHP, if you're familiar. Of course, this function takes Objects whether they are instanceof Array or not.