如何从以下本地 json 文件访问密钥？

Question

I want to access all the keys present in the local json file. When I am using Object.keys(data) it is returnning the 0. I had checked the output in the console,by default the output of json is mapped to 0. So please let me know how can I access the keys.

    public ngOnInit(){
        this._logger.info("Header Mapping Component Initialized");
        this.httpClient.get("applauncher/input.json").subscribe(res=>{
            this.products=res;
            this.keys=Object.keys(this.products);
            console.log("Mapping data",this.keys);
        });


input.json



[
{
    "College1": [
        [
            "Studname1"
        ],
        [
            "Studname2"
        ]
    ],
    "College2": [
        [
            "Stud1"
        ]
    ],
}

]

Answer 1

You can simply do

 const list = [{ "College1": [ [ "Studname1" ], [ "Studname2" ] ], "College2": [ [ "Stud1" ] ], }] const keys = list.map(item => Object.keys(item)); console.log(keys[0]);

Output => ["College1", "College2"]