how to change json key:value

<script>
var json = [{ "id": "5001", "type": "None" },
            { "id": "5002", "type": "Glazed" },
            { "id": "5005", "type": "Sugar" },
            { "id": "5003", "type": "Chocolate" },
            { "id": "5004", "type": "Maple" },
            { "id": "5009", "type": "Juice" }];
/**
 * The function searches over the array by certain field value,
 * and replaces occurences with the parameter provided.
 *
 * @param string field Name of the object field to compare
 * @param string oldvalue Value to compare against
 * @param string newvalue Value to replace mathes with
 */
function replaceByValue( field, oldvalue, newvalue ) {
    for( var k = 0; k < json.length; ++k ) {
        if( oldvalue == json[k][field] ) {
            json[k][field] = newvalue ;
        }
    }
    return json;
}

/**
 * Let's test
 */
console.log(json);

replaceByValue('id','5001','5010')
console.log(json);

replaceByValue('type','Chocolate','only water')
console.log(json);
</script>

Take a look at Pinch, a (multi) data replacement tool for JavaScript objects/JSON. Here is a brief example how pinch.js could be used in your case:

var data = [
  {
    id: 5001,
    type: 'None'
  },
  {
    id: 5002,
    type: 'Glazed'
  },
  {
    id: 5005,
    type: 'Sugar'
  },
  {
    id: 5003,
    type: 'Chocolate'
  },
  {
    id: 5004,
    type: 'Maple'
  },
  {
    id: 5009,
    type: 'Juice'
  }
];

pinch(data, '/id/', function(path, key, value) {
  return (value === 5001) ? 5010 : value;
});