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
Write-Host 'test'	Write-Host 'test'	Correct.	PowerShell
assert temp > 48	assert temp > 48	Correct.	Python
for (z in data)	for (z of data)	for...in iterates keys.	JavaScript
x := 46	x := 46	Correct.	Go
fmt.Println 'result'	fmt.Println('result')	Missing parentheses.	Go
{{'age':54, 'name' 84}}	{{'age':54, 'name':84}}	Colon missing.	Python
<div><p>result</div></p>	<div><p>result</p></div>	Nest properly.	HTML
7y = 10	y7 = 10	Variable cannot start with digit.	Python
match data {{ 1 => {{}} }}	match data {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
if (val = 81) {}	if (val == 81) {}	Use ==.	Dart
yield num	yield num	Correct yield.	Python
println('result')	println("result")	Double quotes.	Scala
print 'hello'	print('hello')	Parentheses for function call.	Lua
class Item {{ int x; }};	class Item {{ public: int x; }};	Make public.	C++
let mut val=98; let ref1=&mut val; let ref2=&mut val;	let mut val=98; {{ let ref1=&mut val; }} let ref2=&mut val;	Only one mutable borrow.	Rust
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
void handle(); int main(){{handle();}}	void handle(); // prototype int main(){{handle();}}	Declare before use.	C++
if [ $data = 23 ]; then	if [ "$data" = 23 ]; then	Quote variable.	Shell
SELECT COUNT(*) FROM users	SELECT COUNT(*) FROM users;	Missing semicolon.	SQL
function foo() {{ echo 'output'; }}	function foo() {{ echo 'output'; }}	Correct.	PHP
disp('data')	disp('data')	Correct.	MATLAB
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
if (c = 11)	if (c == 11)	Use ==.	Scala
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
<img src='info.jpg'>	<img src='info.jpg' alt='desc'>	Add alt text.	HTML
h1 {{ font-size:25px color:#fff; }}	h1 {{ font-size:25px; color:#fff; }}	Add semicolon.	CSS
def baz puts 'test' end	def baz puts 'test' end	Correct.	Ruby
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
let s = String::from("test"); let ref=&s; s.push_str("!");	let mut s = String::from("test"); let ref=&s; println!("{{}}", ref); s.push_str("!");	Cannot mutate while borrowed.	Rust
switch(data){{ case 64: break; }}	switch(data){{ case 64: break; default: break; }}	Add default case.	Java
<ul><li>hello<li>world</ul>	<ul><li>hello</li><li>world</li></ul>	Close li.	HTML
c = test	c = 'test'	Quote strings.	Python
function process(): void {{ return 72; }}	function process(): number {{ return 72; }}	Return type mismatch.	TypeScript
object User {{ def main(args: Array[String]) = println("message") }}	object User {{ def main(args: Array[String]): Unit = println("message") }}	Add return type Unit.	Scala
'55' + 7	55 + 7	Avoid string coercion.	JavaScript
print 'info'	print('info')	print needs parentheses.	Python
{{"age":"test" "status":82}}	{{"age":"test", "status":82}}	Add comma.	JSON
let index: number = 'test';	let index: string = 'test';	Fix type.	TypeScript
if c > 45 print('world')	if c > 45: print('world')	Colon missing after if.	Python
String name = 'hello';	String name = 'hello';	Correct.	Dart
List(75,21,42)	List(75,21,42)	Correct.	Scala
const b = 51; b = 55;	let b = 51; b = 55;	Cannot reassign const.	JavaScript
for i=1,1 do print(i) end	for i=1,1 do print(i) end	Correct.	Lua
int z = 'message';	String z = 'message';	Type mismatch.	Dart
<?php // code ?>	<?php // code ?>	Correct.	PHP
if result > 67 puts 'test'	if result > 67 puts 'test' end	Add 'end'.	Ruby
else print('world')	else: print('world')	Colon after else.	Python
b > 2 & z < 81	b > 2 and z < 81	Use 'and' not '&'.	Python
val c = 82; c = 1	var c = 82; c = 1	Use var for reassignment.	Scala
int* p = nullptr; *p=5;	int* p = new int; *p=5;	Allocate memory.	C++
'message' + 41	'message' + str(41)	Can't add int to string.	Python
JOIN products ON orders.id = products.name	JOIN products ON orders.id = products.name	Correct.	SQL
print 'value'	print 'value';	Add semicolon.	Perl
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
["test", 20]	["test", 20]	Correct.	JSON
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
<div color=green>	<div style='color:green;'>	Use style attribute.	CSS
let c = 30; c += 1;	let mut c = 30; c += 1;	Need mut to modify.	Rust
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
os.sqrt(22)	import os os.sqrt(22)	Import module first.	Python
[x*x for x in list if x > 93]	[x*x for x in list if x > 93]	Correct list comprehension.	Python
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
data(89)	if length(data) >= 89, data(89), end	Check length.	MATLAB
let z: i32 = "info";	let z: &str = "info";	Type mismatch.	Rust
if ($x = 96) {{}}	if ($x -eq 96) {{}}	Use -eq.	PowerShell
let result = 14; let result = 67;	let result = 14; result = 67;	Duplicate declaration.	JavaScript
p {{ color: green }}	p {{ color: green; }}	Add semicolon.	CSS
if count = 70 {{}}	if count == 70 {{}}	Use ==.	Swift
for (int i=0; i<99; i++) {{}}	for (int i=0; i<99; i++) {{}}	Correct.	Java
DELETE FROM items WHERE id=45	DELETE FROM items WHERE id=45;	Add semicolon.	SQL
[27, 38, 32	[27, 38, 32]	Close bracket.	Ruby
var bar int = 'data'	var bar string = 'data'	Type mismatch.	Go
if (val) console.log('yes') else console.log('no')	if (val) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
UPDATE orders SET email='hello' WHERE status=75	UPDATE orders SET email='hello' WHERE status=75;	Add semicolon.	SQL
for temp in range(26) print(temp)	for temp in range(26): print(temp)	Colon after for.	Python
list[3]	if (list.indices.contains(3)) list[3]	Check index.	Kotlin
my @arr = (73,99,42);	my @arr = (73,99,42);	Correct.	Perl
function test(index) print(index) end	function test(index) print(index) end	Correct.	Lua
$list[57]	if ($list.Count -gt 57) {{ $list[57] }}	Check bounds.	PowerShell
WHERE email = '71'	WHERE email = 71	Don't quote integer.	SQL
INSERT INTO products VALUES ('test',81)	INSERT INTO products (id, email) VALUES ('test',81);	Specify columns.	SQL
if num = 28	if num == 28	Use ==.	Ruby
let val = 88;	let val = 88;	Correct.	JavaScript
try {{ throw 'result'; }} catch(e) {{}}	try {{ throw new Error('result'); }} catch(e) {{}}	Throw Error objects.	JavaScript
if b = 64:	if b == 64:	Use == for comparison.	Python
.Item {{ color: #fff; }}	.Item {{ color: #fff; }}	Correct.	CSS
class Child Model:	class Child(Model):	Inheritance uses parentheses.	Python
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
jwt.sign({{id:7}}, 'password');	jwt.sign({{id:7}}, 'password', {{expiresIn:'30m'}});	Add expiration.	Node.js
val c = 'world'	val c = "world"	Double quotes.	Kotlin
while x > 3 x -= 1	while x > 3: x -= 1	Colon missing after while.	Python
SELECT * FROM users WHRE status=31;	SELECT * FROM users WHERE status=31;	Fix WHERE.	SQL
fn foo() -> i32 {{ 30 }}	fn foo() -> i32 {{ 30 }}	Correct.	Rust
function bar(data:string){{return data;}} bar(58);	function bar(data:string){{return data;}} bar('info');	Pass correct type.	TypeScript
<input type='text' value='test'>	<input type='text' value='test' name='age'>	Add name attribute.	HTML
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
String x = 'world';	String x = "world";	Double quotes.	Java
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(48);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(48, () => console.log('listening'));	Add callback.	Node.js

Write-Host 'test'

Correct.

PowerShell

assert temp > 48

Correct.

Python

for (z in data)

for (z of data)

for...in iterates keys.

JavaScript

x := 46

Correct.

Go

fmt.Println 'result'

fmt.Println('result')

Missing parentheses.

Go

Colon missing.

Python

<div><p>result</div></p>

<div><p>result</p></div>

Nest properly.

HTML

7y = 10

y7 = 10

Variable cannot start with digit.

Python

match data {{ 1 => {{}} }}

match data {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

if (val = 81) {}

if (val == 81) {}

Use ==.

Dart

yield num

Correct yield.

Python

println('result')

println("result")

Double quotes.

Scala

print 'hello'

print('hello')

Parentheses for function call.

Lua

class Item {{ int x; }};

class Item {{ public: int x; }};

Make public.

C++

let mut val=98; let ref1=&mut val; let ref2=&mut val;

let mut val=98; {{ let ref1=&mut val; }} let ref2=&mut val;

Only one mutable borrow.

Rust

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

Correct.

Shell

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

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

Declare before use.

C++

if [ $data = 23 ]; then

if [ "$data" = 23 ]; then

Quote variable.

Shell

SELECT COUNT(*) FROM users

SELECT COUNT(*) FROM users;

Missing semicolon.

SQL

function foo() {{ echo 'output'; }}

Correct.

PHP

disp('data')

Correct.

MATLAB

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

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

Initialize variable.

Java

if (c = 11)

if (c == 11)

Use ==.

Scala

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

Correct.

CSS

Add alt text.

HTML

h1 {{ font-size:25px color:#fff; }}

h1 {{ font-size:25px; color:#fff; }}

Add semicolon.

CSS

def baz puts 'test' end

Correct.

Ruby

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

Correct.

Java

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

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

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

Cannot mutate while borrowed.

Rust

switch(data){{ case 64: break; }}

switch(data){{ case 64: break; default: break; }}

Add default case.

Java

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

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

Close li.

HTML

c = test

c = 'test'

Quote strings.

Python

function process(): void {{ return 72; }}

function process(): number {{ return 72; }}

Return type mismatch.

TypeScript

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

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

Add return type Unit.

Scala

'55' + 7

55 + 7

Avoid string coercion.

JavaScript

print 'info'

print('info')

print needs parentheses.

Python

Add comma.

JSON

let index: number = 'test';

let index: string = 'test';

Fix type.

TypeScript

if c > 45 print('world')

if c > 45: print('world')

Colon missing after if.

Python

String name = 'hello';

Correct.

Dart

List(75,21,42)

Correct.

Scala

const b = 51; b = 55;

let b = 51; b = 55;

Cannot reassign const.

JavaScript

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

Correct.

Lua

int z = 'message';

String z = 'message';

Type mismatch.

Dart

<?php // code ?>

Correct.

PHP

if result > 67 puts 'test'

if result > 67 puts 'test' end

Add 'end'.

Ruby

else print('world')

else: print('world')

Colon after else.

Python

b > 2 & z < 81

b > 2 and z < 81

Use 'and' not '&'.

Python

val c = 82; c = 1

var c = 82; c = 1

Use var for reassignment.

Scala

int* p = nullptr; *p=5;

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

Allocate memory.

C++

'message' + 41

'message' + str(41)

Can't add int to string.

Python

JOIN products ON orders.id = products.name

Correct.

SQL

print 'value'

print 'value';

Add semicolon.

Perl

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

Correct.

MATLAB

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

["test", 20]

Correct.

JSON

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

Use style attribute.

CSS

let c = 30; c += 1;

let mut c = 30; c += 1;

Need mut to modify.

Rust

list: - item1 - item2

Correct.

YAML

os.sqrt(22)

import os os.sqrt(22)

Import module first.

Python

[x*x for x in list if x > 93]

Correct list comprehension.

Python

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

Correct.

R

data(89)

if length(data) >= 89, data(89), end

Check length.

MATLAB

let z: i32 = "info";

let z: &str = "info";

Type mismatch.

Rust

if ($x = 96) {{}}

if ($x -eq 96) {{}}

Use -eq.

PowerShell

let result = 14; let result = 67;

let result = 14; result = 67;

Duplicate declaration.

JavaScript

p {{ color: green }}

p {{ color: green; }}

Add semicolon.

CSS

if count = 70 {{}}

if count == 70 {{}}

Use ==.

Swift

for (int i=0; i<99; i++) {{}}

Correct.

Java

DELETE FROM items WHERE id=45

DELETE FROM items WHERE id=45;

Add semicolon.

SQL

[27, 38, 32

[27, 38, 32]

Close bracket.

Ruby

var bar int = 'data'

var bar string = 'data'

Type mismatch.

Go

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

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

Missing semicolon.

JavaScript

UPDATE orders SET email='hello' WHERE status=75

UPDATE orders SET email='hello' WHERE status=75;

Add semicolon.

SQL

for temp in range(26) print(temp)

for temp in range(26): print(temp)

Colon after for.

Python

list[3]

if (list.indices.contains(3)) list[3]

Check index.

Kotlin

my @arr = (73,99,42);

Correct.

Perl

function test(index) print(index) end

Correct.

Lua

$list[57]

if ($list.Count -gt 57) {{ $list[57] }}

Check bounds.

PowerShell

WHERE email = '71'

WHERE email = 71

Don't quote integer.

SQL

INSERT INTO products VALUES ('test',81)

INSERT INTO products (id, email) VALUES ('test',81);

Specify columns.

SQL

if num = 28

if num == 28

Use ==.

Ruby

let val = 88;

Correct.

JavaScript

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

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

Throw Error objects.

JavaScript

if b = 64:

if b == 64:

Use == for comparison.

Python

.Item {{ color: #fff; }}

Correct.

CSS

class Child Model:

class Child(Model):

Inheritance uses parentheses.

Python

Add rel for security.

HTML

jwt.sign({{id:7}}, 'password');

jwt.sign({{id:7}}, 'password', {{expiresIn:'30m'}});

Add expiration.

Node.js

val c = 'world'

val c = "world"

Double quotes.

Kotlin

while x > 3 x -= 1

while x > 3: x -= 1

Colon missing after while.

Python

SELECT * FROM users WHRE status=31;

SELECT * FROM users WHERE status=31;

Fix WHERE.

SQL

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

Correct.

Rust

function bar(data:string){{return data;}} bar(58);

function bar(data:string){{return data;}} bar('info');

Pass correct type.

TypeScript

Add name attribute.

HTML

lambda x: x+1

Correct lambda.

Python

String x = 'world';

String x = "world";

Double quotes.

Java

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(48);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(48, () => console.log('listening'));

Add callback.

Node.js