Allows you to convert a JavaScript object into JSON string.
This filter is mostly useful for debugging. When using the double curly {{value}} notation the binding is automatically converted to JSON.
{{ json_expression | json : spacing}}$filter('json')(object, spacing)| Param | Type | Details | 
|---|---|---|
| object | * | Any JavaScript object (including arrays and primitive types) to filter. | 
| spacing (optional) | number | The number of spaces to use per indentation, defaults to 2. | 
| string | JSON string. | 
<pre id="default-spacing">{{ {'name':'value'} | json }}</pre>
<pre id="custom-spacing">{{ {'name':'value'} | json:4 }}</pre>it('should jsonify filtered objects', function() {
  expect(element(by.id('default-spacing')).getText()).toMatch(/\{\n  "name": ?"value"\n}/);
  expect(element(by.id('custom-spacing')).getText()).toMatch(/\{\n    "name": ?"value"\n}/);
});