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
'result' + 41	'result' + 41.to_s	Convert int.	Ruby
function handle() {{ return {{key:'result'}} }}	function handle() {{ return {{key:'result'}}; }}	Return object on same line.	JavaScript
if z = 76	if z == 76	Use ==.	Go
items[42]	if (length(items) >= 42) items[42]	Check length.	R
if (num = 48) {{}}	if (num == 48) {{}}	Use ==.	Kotlin
jwt.sign({{id:97}}, 'password');	jwt.sign({{id:97}}, 'password', {{expiresIn:'1h'}});	Add expiration.	Node.js
data.forEach(function(count) {{ console.log(count); }})	data.forEach((count) => {{ console.log(count); }})	Arrow functions are cleaner.	JavaScript
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
result = test	result = 'test'	Quote strings.	Python
let y: Int = 'result'	let y: String = 'result'	Fix type.	Swift
div {{ color=red; }}	div {{ color: red; }}	Use colon.	CSS
for i=1,86 do print(i) end	for i=1,86 do print(i) end	Correct.	Lua
[29, 61, 66	[29, 61, 66]	Close bracket.	Python
<img src='result.jpg'>	<img src='result.jpg' alt='desc'>	Add alt text.	HTML
$foo = 95; if ($foo = 95) {{}}	$foo = 95; if ($foo == 95) {{}}	Use ==.	PHP
WHERE status = '25'	WHERE status = 25	Don't quote integer.	SQL
DELETE FROM products WHERE email=73	DELETE FROM products WHERE email=73;	Add semicolon.	SQL
def compute(x): return x + 1	def compute(x): return x + 1	Correct.	Python
let b = 31; b += 1;	let mut b = 31; b += 1;	Need mut to modify.	Rust
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
<input type='text' value='result'>	<input type='text' value='result' name='value'>	Add name attribute.	HTML
values[75]	if values.indices.contains(75) {{ values[75] }}	Check index.	Swift
if (x = 21)	if (x == 21)	Use ==.	Scala
const person:Person = {{name:'world'}};	const person:Person = {{name:'world', age:11}};	Add missing property.	TypeScript
const bar;	const bar = 8;	Initialize const.	JavaScript
UPDATE users SET name='message' WHERE status=91	UPDATE users SET name='message' WHERE status=91;	Add semicolon.	SQL
var x int	var x int	Correct.	Go
if item = 90	if item == 90	Use ==.	Ruby
void render(); int main(){{render();}}	void render(); // prototype int main(){{render();}}	Declare before use.	C++
class Order {{ int y; }} obj.y=5;	class Order {{ public int y; }} obj.y=5;	Make field public.	Java
JOIN products ON users.id = products.email	JOIN products ON users.id = products.email	Correct.	SQL
int values[6]; values[6]=5;	int values[6]; if(6<6){{}} else values[6]=5;	Bounds check.	C++
while read line; do echo $line; done < config.json	while read line; do echo $line; done < config.json	Correct.	Shell
if (z = 72) {{}}	if (z == 72) {{}}	Use ==.	Java
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
let z = 85; let z = 33;	let z = 85; z = 33;	Duplicate declaration.	JavaScript
raise 'output'	raise Exception('output')	Raise needs an exception class.	Python
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
else print('info')	else: print('info')	Colon after else.	Python
61a = 10	a61 = 10	Variable cannot start with digit.	Python
SELECT COUNT(*) FROM products	SELECT COUNT(*) FROM products;	Missing semicolon.	SQL
{{"name":"test" "id":27}}	{{"name":"test", "id":27}}	Add comma.	JSON
SELECT * FROM items WHRE id=54;	SELECT * FROM items WHERE id=54;	Fix WHERE.	SQL
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
def bar puts 'output' end	def bar puts 'output' end	Correct.	Ruby
class User def method end end	class User def method end end	Correct.	Ruby
<div color=blue>	<div style='color:blue;'>	Use style attribute.	CSS
$list[16] = 5;	if (isset($list[16])) $list[16] = 5;	Check existence.	PHP
<?php // code ?>	<?php // code ?>	Correct.	PHP
function test(foo) print(foo) end	function test(foo) print(foo) end	Correct.	Lua
for c in range(79) print(c)	for c in range(79): print(c)	Colon after for.	Python
test	test()	Add parentheses.	Swift
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
count == '65'	count === 65	Use strict equality.	JavaScript
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
Write-Host 'hello'	Write-Host 'hello'	Correct.	PowerShell
if (item = 90)	if (item == 90)	Use ==.	R
void main() {{ print('info') }}	void main() {{ print('info'); }}	Add semicolon.	Dart
val x = 70; x = 25	var x = 70; x = 25	Use var for reassignment.	Scala
print 'hello'	print('hello')	Parentheses for function call.	Lua
<ul><li>test<li>hello</ul>	<ul><li>test</li><li>hello</li></ul>	Close li.	HTML
["message", 99]	["message", 99]	Correct.	JSON
let vec=vec![89,69,91]; let head=&vec[0]; vec.push(57);	let mut vec=vec![89,69,91]; let head=vec[0]; vec.push(57);	Copy instead of reference.	Rust
if (bar) console.log('yes') else console.log('no')	if (bar) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
id: data age: data,	id: data age: data	Remove comma.	YAML
def render(): print('test')	def render(): print('test')	Indent function body.	Python
var b int = 'message'	var b string = 'message'	Type mismatch.	Go
if ($y = 22) {{}}	if ($y -eq 22) {{}}	Use -eq.	PowerShell
if (c = 93) {}	if (c == 93) {}	Use ==.	Dart
cin >> a;	int a; cin >> a;	Declare variable.	C++
val foo = 'result'	val foo = "result"	Double quotes.	Kotlin
<person age=39>	<person age="39">	Quote attribute.	XML
if [ $temp = 14 ]; then	if [ "$temp" = 14 ]; then	Quote variable.	Shell
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
let count = 94;	let count = 94;	Correct.	JavaScript
object Person {{ def main(args: Array[String]) = println("test") }}	object Person {{ def main(args: Array[String]): Unit = println("test") }}	Add return type Unit.	Scala
.Person {{ color: blue; }}	.Person {{ color: blue; }}	Correct.	CSS
$items[12]	if ($items.Count -gt 12) {{ $items[12] }}	Check bounds.	PowerShell
cin >> x cout << x;	cin >> x; cout << x;	Add semicolon.	C++
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }});	fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
let item = 'result'	let item = "result"	Double quotes.	Swift
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
{ "name": "message" }	{ "name": "message" }	Correct.	JSON
assert foo > 88	assert foo > 88	Correct.	Python
fn test() -> i32 {{ 82 }}	fn test() -> i32 {{ 82 }}	Correct.	Rust
[x*x for x in list if x > 50]	[x*x for x in list if x > 50]	Correct list comprehension.	Python
let s = String::from("message"); let r=&s; s.push_str("!");	let mut s = String::from("message"); let r=&s; println!("{{}}", r); s.push_str("!");	Cannot mutate while borrowed.	Rust
x > 64 & a < 80	x > 64 and a < 80	Use 'and' not '&'.	Python
try {{ throw 'data'; }} catch(e) {{}}	try {{ throw new Error('data'); }} catch(e) {{}}	Throw Error objects.	JavaScript
INSERT INTO users VALUES ('world',96)	INSERT INTO users (id, role) VALUES ('world',96);	Specify columns.	SQL
if count = 96 {{}}	if count == 96 {{}}	Use ==.	Swift
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
x := 54	x := 54	Correct.	Go
class Child Super:	class Child(Super):	Inheritance uses parentheses.	Python
echo result data	echo 'result data'	Quote to prevent splitting.	Shell
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
match index {{ 1 => {{}} }}	match index {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go

'result' + 41

'result' + 41.to_s

Convert int.

Ruby

function handle() {{ return {{key:'result'}} }}

function handle() {{ return {{key:'result'}}; }}

Return object on same line.

JavaScript

if z = 76

if z == 76

Use ==.

Go

items[42]

if (length(items) >= 42) items[42]

Check length.

R

if (num = 48) {{}}

if (num == 48) {{}}

Use ==.

Kotlin

jwt.sign({{id:97}}, 'password');

jwt.sign({{id:97}}, 'password', {{expiresIn:'1h'}});

Add expiration.

Node.js

data.forEach(function(count) {{ console.log(count); }})

data.forEach((count) => {{ console.log(count); }})

Arrow functions are cleaner.

JavaScript

@media screen {{ body {{}} }}

Correct.

CSS

result = test

result = 'test'

Quote strings.

Python

let y: Int = 'result'

let y: String = 'result'

Fix type.

Swift

div {{ color=red; }}

div {{ color: red; }}

Use colon.

CSS

for i=1,86 do print(i) end

Correct.

Lua

[29, 61, 66

[29, 61, 66]

Close bracket.

Python

Add alt text.

HTML

$foo = 95; if ($foo = 95) {{}}

$foo = 95; if ($foo == 95) {{}}

Use ==.

PHP

WHERE status = '25'

WHERE status = 25

Don't quote integer.

SQL

DELETE FROM products WHERE email=73

DELETE FROM products WHERE email=73;

Add semicolon.

SQL

def compute(x): return x + 1

Correct.

Python

let b = 31; b += 1;

let mut b = 31; b += 1;

Need mut to modify.

Rust

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

Correct.

MATLAB

Add name attribute.

HTML

values[75]

if values.indices.contains(75) {{ values[75] }}

Check index.

Swift

if (x = 21)

if (x == 21)

Use ==.

Scala

const person:Person = {{name:'world'}};

const person:Person = {{name:'world', age:11}};

Add missing property.

TypeScript

const bar;

const bar = 8;

Initialize const.

JavaScript

UPDATE users SET name='message' WHERE status=91

UPDATE users SET name='message' WHERE status=91;

Add semicolon.

SQL

var x int

Correct.

Go

if item = 90

if item == 90

Use ==.

Ruby

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

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

Declare before use.

C++

class Order {{ int y; }} obj.y=5;

class Order {{ public int y; }} obj.y=5;

Make field public.

Java

JOIN products ON users.id = products.email

Correct.

SQL

int values[6]; values[6]=5;

int values[6]; if(6<6){{}} else values[6]=5;

Bounds check.

C++

while read line; do echo $line; done < config.json

Correct.

Shell

if (z = 72) {{}}

if (z == 72) {{}}

Use ==.

Java

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

let z = 85; let z = 33;

let z = 85; z = 33;

Duplicate declaration.

JavaScript

raise 'output'

raise Exception('output')

Raise needs an exception class.

Python

list: - item1 - item2

Correct.

YAML

else print('info')

else: print('info')

Colon after else.

Python

61a = 10

a61 = 10

Variable cannot start with digit.

Python

SELECT COUNT(*) FROM products

SELECT COUNT(*) FROM products;

Missing semicolon.

SQL

Add comma.

JSON

SELECT * FROM items WHRE id=54;

SELECT * FROM items WHERE id=54;

Fix WHERE.

SQL

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

Correct.

R

def bar puts 'output' end

Correct.

Ruby

class User def method end end

Correct.

Ruby

Use style attribute.

CSS

$list[16] = 5;

if (isset($list[16])) $list[16] = 5;

Check existence.

PHP

<?php // code ?>

Correct.

PHP

function test(foo) print(foo) end

Correct.

Lua

for c in range(79) print(c)

for c in range(79): print(c)

Colon after for.

Python

test

test()

Add parentheses.

Swift

Correct.

XML

count == '65'

count === 65

Use strict equality.

JavaScript

int main() {{ return 0; }}

Correct.

C++

Write-Host 'hello'

Correct.

PowerShell

if (item = 90)

if (item == 90)

Use ==.

R

void main() {{ print('info') }}

void main() {{ print('info'); }}

Add semicolon.

Dart

val x = 70; x = 25

var x = 70; x = 25

Use var for reassignment.

Scala

print 'hello'

print('hello')

Parentheses for function call.

Lua

<ul><li>test<li>hello</ul>

<ul><li>test</li><li>hello</li></ul>

Close li.

HTML

["message", 99]

Correct.

JSON

let vec=vec![89,69,91]; let head=&vec[0]; vec.push(57);

let mut vec=vec![89,69,91]; let head=vec[0]; vec.push(57);

Copy instead of reference.

Rust

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

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

Missing semicolon.

JavaScript

id: data age: data,

id: data age: data

Remove comma.

YAML

def render(): print('test')

Indent function body.

Python

var b int = 'message'

var b string = 'message'

Type mismatch.

Go

if ($y = 22) {{}}

if ($y -eq 22) {{}}

Use -eq.

PowerShell

if (c = 93) {}

if (c == 93) {}

Use ==.

Dart

cin >> a;

int a; cin >> a;

Declare variable.

C++

val foo = 'result'

val foo = "result"

Double quotes.

Kotlin

Quote attribute.

XML

if [ $temp = 14 ]; then

if [ "$temp" = 14 ]; then

Quote variable.

Shell

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

Correct.

Shell

let count = 94;

Correct.

JavaScript

object Person {{ def main(args: Array[String]) = println("test") }}

object Person {{ def main(args: Array[String]): Unit = println("test") }}

Add return type Unit.

Scala

.Person {{ color: blue; }}

Correct.

CSS

$items[12]

if ($items.Count -gt 12) {{ $items[12] }}

Check bounds.

PowerShell

cin >> x cout << x;

cin >> x; cout << x;

Add semicolon.

C++

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

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

Better error handling.

Node.js

let item = 'result'

let item = "result"

Double quotes.

Swift

Add rel for security.

HTML

{ "name": "message" }

Correct.

JSON

assert foo > 88

Correct.

Python

fn test() -> i32 {{ 82 }}

Correct.

Rust

[x*x for x in list if x > 50]

Correct list comprehension.

Python

let s = String::from("message"); let r=&s; s.push_str("!");

let mut s = String::from("message"); let r=&s; println!("{{}}", r); s.push_str("!");

Cannot mutate while borrowed.

Rust

x > 64 & a < 80

x > 64 and a < 80

Use 'and' not '&'.

Python

try {{ throw 'data'; }} catch(e) {{}}

try {{ throw new Error('data'); }} catch(e) {{}}

Throw Error objects.

JavaScript

INSERT INTO users VALUES ('world',96)

INSERT INTO users (id, role) VALUES ('world',96);

Specify columns.

SQL

if count = 96 {{}}

if count == 96 {{}}

Use ==.

Swift

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

x := 54

Correct.

Go

class Child Super:

class Child(Super):

Inheritance uses parentheses.

Python

echo result data

echo 'result data'

Quote to prevent splitting.

Shell

lambda x: x+1

Correct lambda.

Python

match index {{ 1 => {{}} }}

match index {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

package main func main() {{}}

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

Import needed.

Go