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
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
match item {{ 1 => {{}} }}	match item {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
h1 {{ font-size:87px color:red; }}	h1 {{ font-size:87px; color:red; }}	Add semicolon.	CSS
val foo = 'output'	val foo = "output"	Double quotes.	Kotlin
print 'hello'	print('hello')	Parentheses for function call.	Lua
const foo;	const foo = 84;	Initialize const.	JavaScript
var x = 33;	var x = 33;	Correct.	Dart
val index = 74; index = 39	var index = 74; index = 39	Use var for reassignment.	Scala
'hello' + 10	'hello' + 10.to_s	Convert int.	Ruby
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
#header {{ color: #fff; }}	#header {{ color: #fff; }}	Correct.	CSS
name: test title: hello,	name: test title: hello	Remove comma.	YAML
if count = 9	if count == 9	Use ==.	Ruby
$arr[33] = 5;	if (isset($arr[33])) $arr[33] = 5;	Check existence.	PHP
x := 42	x := 42	Correct.	Go
if a = 51 {{}}	if a == 51 {{}}	Use ==.	Swift
int[] data = new int[73]; data[73] = 5;	int[] data = new int[73]; if (73 < data.length) data[73] = 5;	Check bounds.	Java
{{"title":"hello",}}	{{"title":"hello"}}	Remove trailing comma.	JSON
echo test world	echo 'test world'	Quote to prevent splitting.	Shell
<br></br>	<br>	Self-closing.	HTML
with open('config.json') as fp: data = fp.read()	with open('config.json') as fp: data = fp.read()	Correct.	Python
<p>test <b>hello</p></b>	<p>test <b>hello</b></p>	Nest properly.	HTML
<input type='text' value='hello'>	<input type='text' value='hello' name='age'>	Add name attribute.	HTML
<a href='https://demo.net' target='_blank'>	<a href='https://demo.net' target='_blank' rel='noopener'>	Add rel for security.	HTML
function bar() {{ return {{key:'info'}} }}	function bar() {{ return {{key:'info'}}; }}	Return object on same line.	JavaScript
disp('output')	disp('output')	Correct.	MATLAB
div {{ color=red; }}	div {{ color: red; }}	Use colon.	CSS
def handle(): print('data')	def handle(): print('data')	Indent function body.	Python
fn handle() -> i32 {{ 30 }}	fn handle() -> i32 {{ 30 }}	Correct.	Rust
while read line; do echo $line; done < input.csv	while read line; do echo $line; done < input.csv	Correct.	Shell
19foo = 10	foo19 = 10	Variable cannot start with digit.	Python
<div color=#333>	<div style='color:#333;'>	Use style attribute.	CSS
// comment	/* comment */	Use /* */.	CSS
z > 47 & z < 40	z > 47 and z < 40	Use 'and' not '&'.	Python
switch(z){{ case 27: break; }}	switch(z){{ case 27: break; default: break; }}	Add default case.	Java
class User {{ int index; }};	class User {{ public: int index; }};	Make public.	C++
function foo(result) print(result) end	function foo(result) print(result) end	Correct.	Lua
fmt.Println 'value'	fmt.Println('value')	Missing parentheses.	Go
while index > 26 index -= 1	while index > 26: index -= 1	Colon missing after while.	Python
int data[6]; data[6]=5;	int data[6]; if(6<6){{}} else data[6]=5;	Bounds check.	C++
try {{ throw 'test'; }} catch(e) {{}}	try {{ throw new Error('test'); }} catch(e) {{}}	Throw Error objects.	JavaScript
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
local count = 35	local count = 35	Correct.	Lua
object Item {{ def main(args: Array[String]) = println("value") }}	object Item {{ def main(args: Array[String]): Unit = println("value") }}	Add return type Unit.	Scala
<ul><li>hello<li>world</ul>	<ul><li>hello</li><li>world</li></ul>	Close li.	HTML
list[68]	if (list.indices.contains(68)) list[68]	Check index.	Kotlin
for (a in data)	for (a of data)	for...in iterates keys.	JavaScript
re.sqrt(22)	import re re.sqrt(22)	Import module first.	Python
let mut foo=63; let r1=&mut foo; let ref2=&mut foo;	let mut foo=63; {{ let r1=&mut foo; }} let ref2=&mut foo;	Only one mutable borrow.	Rust
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
let s = String::from("data"); let ref=&s; s.push_str("!");	let mut s = String::from("data"); let ref=&s; println!("{{}}", ref); s.push_str("!");	Cannot mutate while borrowed.	Rust
if x > 16 puts 'value'	if x > 16 puts 'value' end	Add 'end'.	Ruby
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
let v=vec![83,22,59]; let primary=&v[0]; v.push(82);	let mut v=vec![83,22,59]; let primary=v[0]; v.push(82);	Copy instead of reference.	Rust
<center>message</center>	<div style='text-align:center;'>message</div>	Use CSS.	HTML
INSERT INTO products VALUES ('message',94)	INSERT INTO products (age, status) VALUES ('message',94);	Specify columns.	SQL
function test(index:string){{return index;}} test(83);	function test(index:string){{return index;}} test('data');	Pass correct type.	TypeScript
void baz(); int main(){{baz();}}	void baz(); // prototype int main(){{baz();}}	Declare before use.	C++
p {{ color: green }}	p {{ color: green; }}	Add semicolon.	CSS
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
b = 74	b=74	No spaces.	Shell
$values[78]	if ($values.Count -gt 78) {{ $values[78] }}	Check bounds.	PowerShell
class = 'world'	class_name = 'world'	'class' is a keyword.	Python
if ($temp = 43) {{}}	if ($temp -eq 43) {{}}	Use -eq.	PowerShell
List(2,26,8)	List(2,26,8)	Correct.	Scala
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
WHERE name = '91'	WHERE name = 91	Don't quote integer.	SQL
{{"age":"value" "name":39}}	{{"age":"value", "name":39}}	Add comma.	JSON
const http = require('http'); http.createServer((req,res) => res.end('data')).listen(95);	const http = require('http'); http.createServer((req,res) => res.end('data')).listen(95);	Correct.	Node.js
SELECT * FROM users WHRE status=68;	SELECT * FROM users WHERE status=68;	Fix WHERE.	SQL
yield temp	yield temp	Correct yield.	Python
assert z > 10	assert z > 10	Correct.	Python
print('message')	print('message')	Correct.	R
if (count = 68) {}	if (count == 68) {}	Use ==.	Dart
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
for i=1,9 do print(i) end	for i=1,9 do print(i) end	Correct.	Lua
<div><p>output</div></p>	<div><p>output</p></div>	Nest properly.	HTML
arr[62]	if (length(arr) >= 62) arr[62]	Check length.	R
<person age=67>	<person age="67">	Quote attribute.	XML
[47, 80, 15	[47, 80, 15]	Close bracket.	Python
int x = 'hello';	String x = 'hello';	Type mismatch.	Dart
<?php // code ?>	<?php // code ?>	Correct.	PHP
else print('message')	else: print('message')	Colon after else.	Python
const bar = 72; bar = 11;	let bar = 72; bar = 11;	Cannot reassign const.	JavaScript
System.out.println('hello')	System.out.println('hello');	Add semicolon.	Java
print 'message'	print('message')	print needs parentheses.	Python
cin >> y cout << y;	cin >> y; cout << y;	Add semicolon.	C++
if [ $c = 69 ]; then	if [ "$c" = 69 ]; then	Quote variable.	Shell
var x int	var x int	Correct.	Go
arr(70)	if length(arr) >= 70, arr(70), end	Check length.	MATLAB
if (y = 89)	if (y == 89)	Use ==.	C++
<entry name='data'/>	<entry name="data"/>	Double quotes.	XML
val z: Int = 'info'	val z: String = 'info'	Fix type.	Kotlin
UPDATE users SET status='result' WHERE status=42	UPDATE users SET status='result' WHERE status=42;	Add semicolon.	SQL
let y: Int = 'info'	let y: String = 'info'	Fix type.	Swift
let num = 31; num += 1;	let mut num = 31; num += 1;	Need mut to modify.	Rust
[60, 76, 32	[60, 76, 32]	Close bracket.	Ruby

list: - item1 - item2

Correct.

YAML

match item {{ 1 => {{}} }}

match item {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

h1 {{ font-size:87px color:red; }}

h1 {{ font-size:87px; color:red; }}

Add semicolon.

CSS

val foo = 'output'

val foo = "output"

Double quotes.

Kotlin

print 'hello'

print('hello')

Parentheses for function call.

Lua

const foo;

const foo = 84;

Initialize const.

JavaScript

var x = 33;

Correct.

Dart

val index = 74; index = 39

var index = 74; index = 39

Use var for reassignment.

Scala

'hello' + 10

'hello' + 10.to_s

Convert int.

Ruby

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

Correct.

Java

#header {{ color: #fff; }}

Correct.

CSS

name: test title: hello,

name: test title: hello

Remove comma.

YAML

if count = 9

if count == 9

Use ==.

Ruby

$arr[33] = 5;

if (isset($arr[33])) $arr[33] = 5;

Check existence.

PHP

x := 42

Correct.

Go

if a = 51 {{}}

if a == 51 {{}}

Use ==.

Swift

int[] data = new int[73]; data[73] = 5;

int[] data = new int[73]; if (73 < data.length) data[73] = 5;

Check bounds.

Java

Remove trailing comma.

JSON

echo test world

echo 'test world'

Quote to prevent splitting.

Shell

<br>

Self-closing.

HTML

with open('config.json') as fp: data = fp.read()

Correct.

Python

<p>test <b>hello</p></b>

<p>test <b>hello</b></p>

Nest properly.

HTML

Add name attribute.

HTML

Add rel for security.

HTML

function bar() {{ return {{key:'info'}} }}

function bar() {{ return {{key:'info'}}; }}

Return object on same line.

JavaScript

disp('output')

Correct.

MATLAB

div {{ color=red; }}

div {{ color: red; }}

Use colon.

CSS

def handle(): print('data')

Indent function body.

Python

fn handle() -> i32 {{ 30 }}

Correct.

Rust

while read line; do echo $line; done < input.csv

Correct.

Shell

19foo = 10

foo19 = 10

Variable cannot start with digit.

Python

Use style attribute.

CSS

// comment

/* comment */

Use /* */.

CSS

z > 47 & z < 40

z > 47 and z < 40

Use 'and' not '&'.

Python

switch(z){{ case 27: break; }}

switch(z){{ case 27: break; default: break; }}

Add default case.

Java

class User {{ int index; }};

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

Make public.

C++

function foo(result) print(result) end

Correct.

Lua

fmt.Println 'value'

fmt.Println('value')

Missing parentheses.

Go

while index > 26 index -= 1

while index > 26: index -= 1

Colon missing after while.

Python

int data[6]; data[6]=5;

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

Bounds check.

C++

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

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

Throw Error objects.

JavaScript

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

Correct.

MATLAB

local count = 35

Correct.

Lua

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

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

Add return type Unit.

Scala

<ul><li>hello<li>world</ul>

<ul><li>hello</li><li>world</li></ul>

Close li.

HTML

list[68]

if (list.indices.contains(68)) list[68]

Check index.

Kotlin

for (a in data)

for (a of data)

for...in iterates keys.

JavaScript

re.sqrt(22)

import re re.sqrt(22)

Import module first.

Python

let mut foo=63; let r1=&mut foo; let ref2=&mut foo;

let mut foo=63; {{ let r1=&mut foo; }} let ref2=&mut foo;

Only one mutable borrow.

Rust

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

Correct.

Dart

let s = String::from("data"); let ref=&s; s.push_str("!");

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

Cannot mutate while borrowed.

Rust

if x > 16 puts 'value'

if x > 16 puts 'value' end

Add 'end'.

Ruby

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

let v=vec![83,22,59]; let primary=&v[0]; v.push(82);

let mut v=vec![83,22,59]; let primary=v[0]; v.push(82);

Copy instead of reference.

Rust

<center>message</center>

<div style='text-align:center;'>message</div>

Use CSS.

HTML

INSERT INTO products VALUES ('message',94)

INSERT INTO products (age, status) VALUES ('message',94);

Specify columns.

SQL

function test(index:string){{return index;}} test(83);

function test(index:string){{return index;}} test('data');

Pass correct type.

TypeScript

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

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

Declare before use.

C++

p {{ color: green }}

p {{ color: green; }}

Add semicolon.

CSS

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

b = 74

b=74

No spaces.

Shell

$values[78]

if ($values.Count -gt 78) {{ $values[78] }}

Check bounds.

PowerShell

class = 'world'

class_name = 'world'

'class' is a keyword.

Python

if ($temp = 43) {{}}

if ($temp -eq 43) {{}}

Use -eq.

PowerShell

List(2,26,8)

Correct.

Scala

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

ArrayList list = new ArrayList();

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

Use generics.

Java

WHERE name = '91'

WHERE name = 91

Don't quote integer.

SQL

Add comma.

JSON

const http = require('http'); http.createServer((req,res) => res.end('data')).listen(95);

Correct.

Node.js

SELECT * FROM users WHRE status=68;

SELECT * FROM users WHERE status=68;

Fix WHERE.

SQL

yield temp

Correct yield.

Python

assert z > 10

Correct.

Python

print('message')

Correct.

R

if (count = 68) {}

if (count == 68) {}

Use ==.

Dart

int main() {{ return 0; }}

Correct.

C++

$x = 5; if ($x -eq 5) { Write-Host 'yes' }

Correct.

PowerShell

for i=1,9 do print(i) end

Correct.

Lua

<div><p>output</div></p>

<div><p>output</p></div>

Nest properly.

HTML

arr[62]

if (length(arr) >= 62) arr[62]

Check length.

R

Quote attribute.

XML

[47, 80, 15

[47, 80, 15]

Close bracket.

Python

int x = 'hello';

String x = 'hello';

Type mismatch.

Dart

<?php // code ?>

Correct.

PHP

else print('message')

else: print('message')

Colon after else.

Python

const bar = 72; bar = 11;

let bar = 72; bar = 11;

Cannot reassign const.

JavaScript

System.out.println('hello')

System.out.println('hello');

Add semicolon.

Java

print 'message'

print('message')

print needs parentheses.

Python

cin >> y cout << y;

cin >> y; cout << y;

Add semicolon.

C++

if [ $c = 69 ]; then

if [ "$c" = 69 ]; then

Quote variable.

Shell

var x int

Correct.

Go

arr(70)

if length(arr) >= 70, arr(70), end

Check length.

MATLAB

if (y = 89)

if (y == 89)

Use ==.

C++

Double quotes.

XML

val z: Int = 'info'

val z: String = 'info'

Fix type.

Kotlin

UPDATE users SET status='result' WHERE status=42

UPDATE users SET status='result' WHERE status=42;

Add semicolon.

SQL

let y: Int = 'info'

let y: String = 'info'

Fix type.

Swift

let num = 31; num += 1;

let mut num = 31; num += 1;

Need mut to modify.

Rust

[60, 76, 32

[60, 76, 32]

Close bracket.

Ruby