i have pushed data to an array like this
this.data.push{'data': 'type',
'value': 'apple'}
this.data[index].value.push = 'banana';
Adding items to arrays work like this in javascript:
this.data.push({'data': 'type', 'value': 'apple'});
However, given that your data is an object, you don't need to use push:
this.data[index].value = 'banana';
You can access a value from a javascript object directly.
Given that you have used string keys, you will probably have to do the following:
this.data[index]['value'] = 'banana';
Look at this for more info: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_Objects