foreach for javascript，json数组

Question

I have a JSON array that looks like this:

[{"RegDate":"31-03-2011"},{"RegDate":"29-07-2011"},{"RegDate":"09-08-2011"},{"RegDate":"09-08-2011"},{"RegDate":"09-08-2011"},{"RegDate":"12-08-2011"},{"RegDate":"15-08-2011"},{"RegDate":"15-08-2011"},{"RegDate":"23-08-2011"},{"RegDate":"07-09-2011"},{"RegDate":"09-09-2011"},{"RegDate":"13-10-2011"},{"RegDate":"13-10-2011"},{"RegDate":"13-10-2011"},{"RegDate":"25-10-2011"},{"RegDate":"25-10-2011"},{"RegDate":"03-11-2011"},{"RegDate":"03-11-2011"},{"RegDate":"11-11-2011"},{"RegDate":"16-11-2011"},{"RegDate":"18-11-2011"},{"RegDate":"21-11-2011"},{"RegDate":"02-12-2011"},{"RegDate":"02-12-2011"},{"RegDate":"12-12-2011"}]

The code to get this json array is as of the following:

var unavailableDates1 = jQuery.parseJSON('<?php echo json_encode($noticesDates) ?>');

I am trying too get all of the dates in that array (which was originally a multidimensional array), and put it inside one array:

var unavailableDates = ["9-3-2012", "14-3-2012", "15-3-2012"]; for example

I am unsure of how to do this, I have tried a foreach but wasn't successful.

All help will be appreciated.

Answer 1

First of all, that parseJSON is unnecessary and actually dangerous. Take it out:

var unavailableDates1 = <?php echo json_encode($noticesDates) ?>;

Then, just use jQuery.map :

var unavailableDates = $.map(unavailableDates1, function(item) {
    return item.RegDate;
});

---

Using a string like that is dangerous for the following three objects, for example:

• {"key":"Backslash here: \\\\"}
• {"key":"I'm a horse!"}
• {"key":"Some\\\\backslash"}

They become, respectively:

• SyntaxError: Unexpected end of input (Single escape escapes end of string)
• SyntaxError: Unexpected identifier (Unescaped single quote breaks out of the string, actually an XSS vulnerability )
• Object
  key: "Someackslash" ( \\\\b becomes the \\b backspace control character)
  __proto__: Object

You could escape it again, but there's no need; valid JSON is always a valid JavaScript object, and you can trust your own PHP not to include injection code in there.

Answer 2

var justDates = [];
for (var i=0; i < unavailableDates1.length; i++) {
   justDates.push(unavailableDates1[i]['RegDate']);
}

Each Object ({'RegDate:'date'}) is an item in a javascript array. To get an item you use a numerical index. so to get the first item would be theArray[0] this would give you {"RegDate":"31-03-2011"} . Then to get that particular date string you just have to use the key theArray[0]['RegDate'] !. So since you want to go through every member of a list, you should get the list length using .length .

For loops are usually used for this type of iteration and not for..in. because for in can access properties that are undesired! http://javascriptweblog.wordpress.com/2011/01/04/exploring-javascript-for-in-loops/

Answer 3

have a look at how to iterate over an array . You can do something like:

dates = new Array();
unavailableDates1.forEach(function (obj){ 
    dates.push(obj.RegDate);
};

Answer 4

Try the following:

JavaScript:

var x = [{"RegDate":"31-03-2011"},{"RegDate":"29-07-2011"},{"RegDate":"09-08-2011"},{"RegDate":"09-08-2011"},{"RegDate":"09-08-2011"},{"RegDate":"12-08-2011"},{"RegDate":"15-08-2011"},{"RegDate":"15-08-2011"},{"RegDate":"23-08-2011"},{"RegDate":"07-09-2011"},{"RegDate":"09-09-2011"},{"RegDate":"13-10-2011"},{"RegDate":"13-10-2011"},{"RegDate":"13-10-2011"},{"RegDate":"25-10-2011"},{"RegDate":"25-10-2011"},{"RegDate":"03-11-2011"},{"RegDate":"03-11-2011"},{"RegDate":"11-11-2011"},{"RegDate":"16-11-2011"},{"RegDate":"18-11-2011"},{"RegDate":"21-11-2011"},{"RegDate":"02-12-2011"},{"RegDate":"02-12-2011"},{"RegDate":"12-12-2011"}];
var ary = new Array();
for (foo in x) {
    ary.push(x[foo].RegDate);
}
console.log(ary);

jsFiddle example .

Answer 5

I noticed you tag jquery in here as well so, here's a jquery solution:

http://jsfiddle.net/aztechy/DK9KM/

var foo = [
  {"RegDate":"31-03-2011"},
  {"RegDate":"29-07-2011"},
  {"RegDate":"09-08-2011"},
  {"RegDate":"09-08-2011"}
];

var datesArray = [];
$.each(foo, function() {
  datesArray.push(this.RegDate);
});

console.log(datesArray);​

Answer 6

Try This, it may works.

var unavailableDates = [];
for(var i = 0; i < unavailableDates1.length; i++){
    unavailableDates[i] = unavailableDates1[i].RegDate;
}

Answer 7

for(var i=0;i<unavailableDates.length;i++) {
    unavailableDates[i] = unavailableDates[i].RegDate;
}