如何使用 JavaScript 编辑本地 JSON 文件

Question

Please answer me as example Select code

1. I want to add values into array local file JSON (insert member to JSON)
2. element is also replaced my element like type , name ... in JSON (update member in JSON)
3. delete number line where id="1" and email="amir@site.com" (delete memebr in JSON)

JSON file : report.json

var amir='{"reports":[' +
    '{"id": "1","type": "admin","name": "amir","email": "amir@site.com","password": "123"},' +
    '{"id": "2","type": "member","name": "kevin","email": "ad@ad.com","password": "1234"}]}';

example select code for check register admin :

var obj = JSON.parse(amir);
for(c = 0; c <= obj.reports.length - 1; c++) {
    type = obj.reports[c].type.toString();
    if (type == "admin") {
        active = 1;
    }

    if (c == obj.reports.length - 1) {
        if (active == 1)
            alert("Yes");
        else
            alert("No");
    }
}

Answer 1

As far as saving the result of manipulated JSON to the disk, that has to be done on the back end, or you can open a window with the file as content, setting the MIME type to json, which could prompt the user to save it to their computer, depending on their browser settings. See http://www.w3schools.com/jsref/met_doc_open.asp .

See below for manipulation of JSON object.

 var amir='{"reports":[' + '{"id": "1","type": "admin","name": "amir","email": "amir@site.com","password": "123"},' + '{"id": "2","type": "member","name": "kevin","email": "ad@ad.com","password": "1234"}]}'; var obj = JSON.parse(amir); document.getElementById("before").innerHTML = JSON.stringify(obj); console.log("Before", JSON.parse(JSON.stringify(obj))); // objects use pointers, clone it to see the value at this point // Add a new member into the array (example, using made up values) obj.reports.push({ "id": ""+obj.reports.length + 1, "type": "member", "name": "Joe", "email": "asdf@gmail.com", "password": "ajdj12oi42" }); document.getElementById("during").innerHTML = JSON.stringify(obj); console.log("During", JSON.parse(JSON.stringify(obj))); // objects use pointers, clone it to see the value at this point // When deleting items, it is often easier to start high, and end low for(var c = obj.reports.length - 1; c >= 0; c--) { // Delete member in JSON where id == 1 and email == amir@site.com if(obj.reports[c].id == "1" && obj.reports[c].email == "amir@site.com") { obj.reports.splice(c, 1); } else { // Add values into the objects (example, using random numbers) obj.reports[c].newKey = "New Value! " + Math.floor(Math.random() * 100); } } document.getElementById("after").innerHTML = JSON.stringify(obj); console.log("After", JSON.parse(JSON.stringify(obj))); // objects use pointers, clone it to see the value at this point

 <h1>Before</h1> <div id="before"></div> <h1>During</h1> <div id="during"></div> <h1>After</h1> <div id="after"></div>