Visual Studio Code – Replace everything after a current occurrence in VS Code find/replace

I don’t think you can search and replace with this kind of logic
directly inside Visual Studio Code. Using a regular expression with
a positive lookbehind would be a way to achieve it, but unfortunately
this will only work if the lookbehind has a fixed length.

But for your simple case, you can select the last part of your file and
only search and replace in the selection:

On some regex engines, use could use a lookbehind

In some JavaScript engines (the case in my Chrome), you are allowed
to use a variable length lookbehind. A demo here:

https://regex101.com/r/O1iOhc/1

The idea is to search for "year": 2020 only if it is preceded by
"year": 2020 and anything else.

For elaborated search and replacements : program it!

To do more sophisticated search and replacements, you’ll need to do
a bit of programming. Typically, in JavaScript, you can use a
callback function instead of a replacement string. This way, you
can use a counter or do anything complicated for the replacement.

Here, I captured the field name and the separator in a first capturing
group and any year (digits) in a second capturing group. The callback
function will receive the full match as the first argument and then
the capturing groups as other arguments. My logic is to take the
current year and increment it by one, but only for occurrences
higher than 1. Of course, the mathematical operation of year
increment is just here as an example, to show you what it can bring
compared to an IDE.

const json = `[
  {
    "MyField": "Hello World",
    "Year": 2020
  },
  {
    "MyField": "foo bar",
    "Year": 2020
  },
  {
    "MyField": "mystring1",
    "Year": 2020
  }
]
`;

// Regular expression with a capturing group for the field name, some
// optional spaces, the double-point and a second capturing group for
// the numeric value.
const regex = /(?<name>"Year"s*:s*)(?<value>d+)/g;

let occurrence = 1;

// Use a callback function for the replacement value so that we
// can do some more elaborated logic.
const result = json.replace(regex, (fullMatch, name, value) => {
  if (occurrence++ > 1) {
    let year = parseInt(value);
    return name + (String)(year + 1);
  } else {
    return fullMatch;
  }
});

console.log(result);