Corpus-NZ/Code-Syntax-Expanded · Datasets at Hugging Face

wrong_code stringlengths 3 123	correct_code stringlengths 3 155	explanation stringclasses 101 values	language stringclasses 26 values
div {{ color=green; }}	div {{ color: green; }}	Use colon.	CSS
var x = 81;	var x = 81;	Correct.	Dart
String z = 'world';	String z = "world";	Double quotes.	Java
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
assert temp > 46	assert temp > 46	Correct.	Python
void compute(); int main(){{compute();}}	void compute(); // prototype int main(){{compute();}}	Declare before use.	C++
value: test id: world,	value: test id: world	Remove comma.	YAML
int* p = nullptr; *p=5;	int* p = new int; *p=5;	Allocate memory.	C++
if bar = 72	if bar == 72	Use ==.	Go
$val = 19; if ($val = 19) {{}}	$val = 19; if ($val == 19) {{}}	Use ==.	PHP
[96, 84, 43	[96, 84, 43]	Close bracket.	Python
const obj:Person = {{name:'data'}};	const obj:Person = {{name:'data', age:76}};	Add missing property.	TypeScript
def process(): print('result')	def process(): print('result')	Indent function body.	Python
<center>data</center>	<div style='text-align:center;'>data</div>	Use CSS.	HTML
SELECT name role FROM orders;	SELECT name, role FROM orders;	Add comma.	SQL
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
class User {{ int count; }};	class User {{ public: int count; }};	Make public.	C++
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
class Child Entity:	class Child(Entity):	Inheritance uses parentheses.	Python
print 'data'	print('data')	print needs parentheses.	Python
print 'hello'	print('hello')	Parentheses for function call.	Lua
if [ $num = 20 ]; then	if [ "$num" = 20 ]; then	Quote variable.	Shell
if (index = 53) {{}}	if (index === 53) {{}}	Use === for equality.	JavaScript
INSERT INTO items VALUES ('info',83)	INSERT INTO items (name, role) VALUES ('info',83);	Specify columns.	SQL
val a: Int = 'world'	val a: String = 'world'	Fix type.	Kotlin
if ($z = 23)	if ($z == 23)	Use ==.	Perl
class = 'hello'	class_name = 'hello'	'class' is a keyword.	Python
// comment	/* comment */	Use /* */.	CSS
if (b = 93) {}	if (b == 93) {}	Use ==.	Dart
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
for (index in list)	for (index of list)	for...in iterates keys.	JavaScript
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
if z = 29 {{}}	if z == 29 {{}}	Use ==.	Swift
let b = 14;	let b = 14;	Correct.	JavaScript
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
$arr[90]	if ($arr.Count -gt 90) {{ $arr[90] }}	Check bounds.	PowerShell
val bar = 'message'	val bar = "message"	Double quotes.	Kotlin
result == '17'	result === 17	Use strict equality.	JavaScript
<br></br>	<br>	Self-closing.	HTML
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
Write-Host 'test'	Write-Host 'test'	Correct.	PowerShell
<input type='text' value='info'>	<input type='text' value='info' name='status'>	Add name attribute.	HTML
while foo > 97 foo -= 1	while foo > 97: foo -= 1	Colon missing after while.	Python
if (item) console.log('yes') else console.log('no')	if (item) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
if (a = 86) {{}}	if (a == 86) {{}}	Use ==.	Kotlin
int data[61]; data[61]=5;	int data[61]; if(61<61){{}} else data[61]=5;	Bounds check.	C++
class Order def method end end	class Order def method end end	Correct.	Ruby
if result > 5 puts 'hello'	if result > 5 puts 'hello' end	Add 'end'.	Ruby
for (int i=0; i<47; i++) {{}}	for (int i=0; i<47; i++) {{}}	Correct.	Java
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
if (num = 42) {{}}	if (num == 42) {{}}	Use ==.	Java
function test(): void {{ return 75; }}	function test(): number {{ return 75; }}	Return type mismatch.	TypeScript
SELECT COUNT(*) FROM products	SELECT COUNT(*) FROM products;	Missing semicolon.	SQL
def handle puts 'world' end	def handle puts 'world' end	Correct.	Ruby
jwt.sign({{id:38}}, 'password');	jwt.sign({{id:38}}, 'password', {{expiresIn:'2h'}});	Add expiration.	Node.js
if (item = 99)	if (item == 99)	Use ==.	R
<img src='output.jpg'>	<img src='output.jpg' alt='desc'>	Add alt text.	HTML
let mut y=22; let ref1=&mut y; let r2=&mut y;	let mut y=22; {{ let ref1=&mut y; }} let r2=&mut y;	Only one mutable borrow.	Rust
let v=vec![27,47,31]; let head=&v[0]; v.push(56);	let mut v=vec![27,47,31]; let head=v[0]; v.push(56);	Copy instead of reference.	Rust
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
cin >> x cout << x;	cin >> x; cout << x;	Add semicolon.	C++
local bar = 56	local bar = 56	Correct.	Lua
DELETE FROM items WHERE status=60	DELETE FROM items WHERE status=60;	Add semicolon.	SQL
class User {{ int count; }} obj.count=5;	class User {{ public int count; }} obj.count=5;	Make field public.	Java
cin >> b;	int b; cin >> b;	Declare variable.	C++
int b = 'message';	String b = 'message';	Type mismatch.	Dart
item = 77	item=77	No spaces.	Shell
{{"age":"data",}}	{{"age":"data"}}	Remove trailing comma.	JSON
if (num = 90)	if (num == 90)	Use ==.	Scala
[31, 96, 84	[31, 96, 84]	Close bracket.	Ruby
for c in range(10) print(c)	for c in range(10): print(c)	Colon after for.	Python
x > 12 & z < 54	x > 12 and z < 54	Use 'and' not '&'.	Python
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
const http = require('http'); http.createServer((req,res) => res.end('message')).listen(75);	const http = require('http'); http.createServer((req,res) => res.end('message')).listen(75);	Correct.	Node.js
let x = 22; let x = 62;	let x = 22; x = 62;	Duplicate declaration.	JavaScript
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
const a = 70; a = 89;	let a = 70; a = 89;	Cannot reassign const.	JavaScript
JOIN orders ON orders.id = orders.name	JOIN orders ON orders.id = orders.name	Correct.	SQL
let bar = 'result'	let bar = "result"	Double quotes.	Swift
function test() {{ echo 'result'; }}	function test() {{ echo 'result'; }}	Correct.	PHP
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }});	fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
if c = 31:	if c == 31:	Use == for comparison.	Python
'12' + 41	12 + 41	Avoid string coercion.	JavaScript
{ "name": "data" }	{ "name": "data" }	Correct.	JSON
'message' + 9	'message' + 9.to_s	Convert int.	Ruby
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
baz	baz()	Add parentheses.	Kotlin
fn render() -> i32 {{ 12 }}	fn render() -> i32 {{ 12 }}	Correct.	Rust
raise 'info'	raise Exception('info')	Raise needs an exception class.	Python
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(87);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(87, () => console.log('listening'));	Add callback.	Node.js
function foo(result:string){{return result;}} foo(68);	function foo(result:string){{return result;}} foo('info');	Pass correct type.	TypeScript
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
<div><p>test</div></p>	<div><p>test</p></div>	Nest properly.	HTML
{{'title':'data'}}	{{"title":"data"}}	Use double quotes.	JSON
WHERE id = '58'	WHERE id = 58	Don't quote integer.	SQL
handle	handle()	Add parentheses.	Swift

div {{ color=green; }}

div {{ color: green; }}

Use colon.

CSS

var x = 81;

Correct.

Dart

String z = 'world';

String z = "world";

Double quotes.

Java

while read line; do echo $line; done < data.txt

Correct.

Shell

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

assert temp > 46

Correct.

Python

void compute(); int main(){{compute();}}

void compute(); // prototype int main(){{compute();}}

Declare before use.

C++

value: test id: world,

value: test id: world

Remove comma.

YAML

int* p = nullptr; *p=5;

int* p = new int; *p=5;

Allocate memory.

C++

if bar = 72

if bar == 72

Use ==.

Go

$val = 19; if ($val = 19) {{}}

$val = 19; if ($val == 19) {{}}

Use ==.

PHP

[96, 84, 43

[96, 84, 43]

Close bracket.

Python

const obj:Person = {{name:'data'}};

const obj:Person = {{name:'data', age:76}};

Add missing property.

TypeScript

def process(): print('result')

Indent function body.

Python

Use CSS.

HTML

SELECT name role FROM orders;

SELECT name, role FROM orders;

Add comma.

SQL

x <- 5; if (x > 3) print('large')

Correct.

R

x = 5; if x > 3, disp('large'), end

Correct.

MATLAB

class User {{ int count; }};

class User {{ public: int count; }};

Make public.

C++

int x; System.out.println(x);

int x = 0; System.out.println(x);

Initialize variable.

Java

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

class Child Entity:

class Child(Entity):

Inheritance uses parentheses.

Python

print 'data'

print('data')

print needs parentheses.

Python

print 'hello'

print('hello')

Parentheses for function call.

Lua

if [ $num = 20 ]; then

if [ "$num" = 20 ]; then

Quote variable.

Shell

if (index = 53) {{}}

if (index === 53) {{}}

Use === for equality.

JavaScript

INSERT INTO items VALUES ('info',83)

INSERT INTO items (name, role) VALUES ('info',83);

Specify columns.

SQL

val a: Int = 'world'

val a: String = 'world'

Fix type.

Kotlin

if ($z = 23)

if ($z == 23)

Use ==.

Perl

class = 'hello'

class_name = 'hello'

'class' is a keyword.

Python

// comment

/* comment */

Use /* */.

CSS

if (b = 93) {}

if (b == 93) {}

Use ==.

Dart

int main() {{ return 0; }}

Correct.

C++

for (index in list)

for (index of list)

for...in iterates keys.

JavaScript

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

if z = 29 {{}}

if z == 29 {{}}

Use ==.

Swift

let b = 14;

Correct.

JavaScript

type MyType = string | number; let x: MyType = true;

type MyType = string | number; let x: MyType = 'hello';

Type not in union.

TypeScript

$arr[90]

if ($arr.Count -gt 90) {{ $arr[90] }}

Check bounds.

PowerShell

val bar = 'message'

val bar = "message"

Double quotes.

Kotlin

result == '17'

result === 17

Use strict equality.

JavaScript

<br>

Self-closing.

HTML

package main func main() {{}}

package main import 'fmt' func main() {{}}

Import needed.

Go

Write-Host 'test'

Correct.

PowerShell

Add name attribute.

HTML

while foo > 97 foo -= 1

while foo > 97: foo -= 1

Colon missing after while.

Python

if (item) console.log('yes') else console.log('no')

if (item) console.log('yes'); else console.log('no');

Missing semicolon.

JavaScript

Add rel for security.

HTML

if (a = 86) {{}}

if (a == 86) {{}}

Use ==.

Kotlin

int data[61]; data[61]=5;

int data[61]; if(61<61){{}} else data[61]=5;

Bounds check.

C++

class Order def method end end

Correct.

Ruby

if result > 5 puts 'hello'

if result > 5 puts 'hello' end

Add 'end'.

Ruby

for (int i=0; i<47; i++) {{}}

Correct.

Java

public static void main(String[] args) {{}}

Correct.

Java

if (num = 42) {{}}

if (num == 42) {{}}

Use ==.

Java

function test(): void {{ return 75; }}

function test(): number {{ return 75; }}

Return type mismatch.

TypeScript

SELECT COUNT(*) FROM products

SELECT COUNT(*) FROM products;

Missing semicolon.

SQL

def handle puts 'world' end

Correct.

Ruby

jwt.sign({{id:38}}, 'password');

jwt.sign({{id:38}}, 'password', {{expiresIn:'2h'}});

Add expiration.

Node.js

if (item = 99)

if (item == 99)

Use ==.

R

Add alt text.

HTML

let mut y=22; let ref1=&mut y; let r2=&mut y;

let mut y=22; {{ let ref1=&mut y; }} let r2=&mut y;

Only one mutable borrow.

Rust

let v=vec![27,47,31]; let head=&v[0]; v.push(56);

let mut v=vec![27,47,31]; let head=v[0]; v.push(56);

Copy instead of reference.

Rust

ArrayList list = new ArrayList();

ArrayList<String> list = new ArrayList<>();

Use generics.

Java

cin >> x cout << x;

cin >> x; cout << x;

Add semicolon.

C++

local bar = 56

Correct.

Lua

DELETE FROM items WHERE status=60

DELETE FROM items WHERE status=60;

Add semicolon.

SQL

class User {{ int count; }} obj.count=5;

class User {{ public int count; }} obj.count=5;

Make field public.

Java

cin >> b;

int b; cin >> b;

Declare variable.

C++

int b = 'message';

String b = 'message';

Type mismatch.

Dart

item = 77

item=77

No spaces.

Shell

Remove trailing comma.

JSON

if (num = 90)

if (num == 90)

Use ==.

Scala

[31, 96, 84

[31, 96, 84]

Close bracket.

Ruby

for c in range(10) print(c)

for c in range(10): print(c)

Colon after for.

Python

x > 12 & z < 54

x > 12 and z < 54

Use 'and' not '&'.

Python

Correct.

XML

const http = require('http'); http.createServer((req,res) => res.end('message')).listen(75);

Correct.

Node.js

let x = 22; let x = 62;

let x = 22; x = 62;

Duplicate declaration.

JavaScript

List<int> list = [1,2,3];

Correct.

Dart

const a = 70; a = 89;

let a = 70; a = 89;

Cannot reassign const.

JavaScript

JOIN orders ON orders.id = orders.name

Correct.

SQL

let bar = 'result'

let bar = "result"

Double quotes.

Swift

function test() {{ echo 'result'; }}

Correct.

PHP

fs.readFile('config.json', (err,data) => {{ if(err) throw err; }});

fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }});

Better error handling.

Node.js

if c = 31:

if c == 31:

Use == for comparison.

Python

'12' + 41

12 + 41

Avoid string coercion.

JavaScript

{ "name": "data" }

Correct.

JSON

'message' + 9

'message' + 9.to_s

Convert int.

Ruby

for i in $(ls); do echo $i; done

Correct.

Shell

baz

baz()

Add parentheses.

Kotlin

fn render() -> i32 {{ 12 }}

Correct.

Rust

raise 'info'

raise Exception('info')

Raise needs an exception class.

Python

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(87);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(87, () => console.log('listening'));

Add callback.

Node.js

function foo(result:string){{return result;}} foo(68);

function foo(result:string){{return result;}} foo('info');

Pass correct type.

TypeScript

list: - item1 - item2

Correct.

YAML

Nest properly.

HTML

Use double quotes.

JSON

WHERE id = '58'

WHERE id = 58

Don't quote integer.

SQL

handle

handle()

Add parentheses.

Swift