javascript将JSON字符串转换为JSON对象

Question

I al using javascript and looping through the values of a submitted form and trying to build a son object out of the form values.

This is an example of the final object I need:

{
  "DataObject": {
    "user": { "-name": "username" },
    "contentFile": {
      "-filename": "Breaking_News",
      "lock": { "-fileIsBeingEdited": "false" },
      "content": {
        "line": [
          {
            "-index": "1",
            "-text": "this is the header"
          },
          {
            "-index": "2",
            "-text": "this is the first line"
          },
          {
            "-index": "3",
            "-text": "this is the second line"
          }
        ]
      }
    }
  }
}

So far i am adding all of this data to a string as that seems to be the only way i can insert the form values (the line array) into the middle of the object.

var jsonStr = '{'
       + 'iceteaDataObject: {'
        + 'user: {"-name": "hindsc52"},'
          + 'contentFile: {'
          + '"-filename": "Ticker",'
          + 'lock: { "-fileIsBeingEdited": "false" },'
          + 'content: {'
          +  'line: ['

    for(var i = 0; i < elem.length; i++) {
      if(!elem[i].value == '') {
        jsonStr += '{'
        jsonStr += "-index: " + i + ',';
        jsonStr += "-text: " + elem[i].value;
        jsonStr += '},'
      }
    }

    jsonStr += ']}}}}';

    console.log(JSON.parse(jsonData));

however when running this I get the error: unexpected token 'i'.

I have tried to use stringily but then just outputs the entire sting again.

Answer 1

You don't need or want JSON for this, just build the object:

 // Sample data var elem = [{ value: "one" }, { value: "two" }]; // Build the object var obj = { "DataObject": { "user": { "-name": "username" }, "contentFile": { "-filename": "Breaking_News", "lock": { "-fileIsBeingEdited": "false" }, "content": { "line": [] } } } }; var line = obj.DataObject.contentFile.content.line; elem.forEach(function(entry, index) { if (entry.value != '') { line.push({ "-index": index, "-text": entry.value }); } }); // Show result: document.body.innerHTML = "<pre>" + JSON.stringify(obj, null, 2) + "</pre>"; 

---

Side note: You don't check for blank strings like this:

if (!entry.value == '') { // <== Incorrect

You can use:

if (entry.value != '') {

or:

if (entry.value) {

Answer 2

You shouldn't build JSON like this, but use JSON.stringify() (see MDN doc ) instead:

var myObject={foo:"bar"};
var myJSON=JSON.stringify(myObject);
console.log(myJSON); //echo {"foo":"bar"}

Answer 3

Here is an alternative way:

var json = {
  iceteaDataObject: {
    "-name": "hindsc52"
  },
  contentFile: {
    "-filename": "Ticker",
    lock: { "-fileIsBeingEdited": "false" },
    content: {line: []}
  }
}
for(var i = 0; i < elem.length; i++) {
      if(!elem[i].value == '') {
        json.contentFile.content.line.push({"-index": i,"-text": elem[i].value }
      }
    }
var jsonStr = JSON.stringify(json);

Answer 4

You need to put all your keys in quotes for this to work. As the others have pointed out though, you are not really supposed to do this.

If you still want to do it your way, try this:

var jsonStr = '{'
      + '"iceteaDataObject": {'
      + '"user": {"-name": "hindsc52"},'
      + '"contentFile": {'
      + '"-filename": "Ticker",'
      + '"lock": { "-fileIsBeingEdited": "false" },'
      + '"content": {'
      +  '"line": ['

for(var i = 0; i < elem.length; i++) {
  if(!elem[i].value == '') {
    jsonStr += '{'
    jsonStr += '"-index": ' + i + ',';
    jsonStr += '"-text": ' + '"' + elem[i].value + '"';
    jsonStr += '},'
  }
}

jsonStr += ']}}}}';