What is the regex for json null?

The regex pattern for json null is `^null$`. This pattern validates json null literal.

How do I use this regex in JavaScript?

In JavaScript, create the regex with `const regex = /^null$/;` and test with `regex.test(yourValue)`. It returns `true` if the value matches.

How do I use this regex in Python?

In Python, use `import re; re.match(r'^null$', value)`. The raw string prefix (`r`) prevents Python from interpreting backslashes as escape characters.

Is this regex case-sensitive?

By default, yes. To make it case-insensitive, add the `i` flag in JavaScript (`/^null$/i`) or use `re.IGNORECASE` in Python.

Regex for JSON Null

Regex Pattern

^null$

JSON null literal

Quick Answer

The regex pattern for json null is `^null$`. JSON null literal. This works in JavaScript, Python, Ruby, PHP, Java, and most regex engines that support PCRE syntax.

Test Examples

Input	Result
null	✓ Matches
Null	✗ No match
NULL	✗ No match
undefined	✗ No match
nil	✗ No match
None	✗ No match

Code Examples

javascript

const regex = /^null$/;
const isValid = regex.test(value);

python

import re
pattern = r'^null$'
if re.match(pattern, value):
    print("valid")

ruby

pattern = /^null$/
if value =~ pattern
  puts "valid"
end

php

if (preg_match('/^null$/', $value)) {
    echo "valid";
}

java

String pattern = "^null$";
boolean isValid = value.matches(pattern);

Frequently Asked Questions

Related Regex Patterns

JavaScript Variable Name

Valid JavaScript variable/identifier name

Python Variable Name

Valid Python identifier name

CSS Class Name

Valid CSS class name (starts with letter, underscore, or hyphen)

CSS ID Selector

CSS ID selector starting with #

JSON Key

JSON object key (quoted string followed by colon)

Semantic Version (Strict)

Strict semantic versioning (MAJOR.MINOR.PATCH)