Are multi-line strings allowed in JSON?

Standard JSON does not natively support multi-line strings. In JSON, all string values must be on a single line and enclosed in double quotes. To represent multi-line text in JSON, you typically use the escape character to represent newlines.

For example, if we want to represent the following multi-line string:

First
Second line
Third line```

In JSON, you would write:

```json
{
  "multiLineString": "First line\nSecond line\nThird line"
}

When this JSON is parsed, the parser will recognize the escape sequence and handle the string as multi-line when used.

However, it's worth noting that in some programming environments, you might leverage the language's native multi-line string support before constructing the JSON string. Then, when embedding this multi-line string into the JSON structure, your code will convert it to a single line by inserting to represent line breaks.

Here is an example in JavaScript handling multi-line strings and converting them to JSON-compatible format:

javascript
let text = `First line
Second line
Third line`;

let json = JSON.stringify({ multiLineString: text });
console.log(json);  // Output: {"multiLineString":"First line\nSecond line\nThird line"}