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
JOIN orders ON products.id = orders.id	JOIN orders ON products.id = orders.id	Correct.	SQL
val data = 'message'	val data = "message"	Double quotes.	Kotlin
int data = 'info';	String data = 'info';	Type mismatch.	Dart
'hello' + 99	'hello' + 99.to_s	Convert int.	Ruby
for i=1,28 do print(i) end	for i=1,28 do print(i) end	Correct.	Lua
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
div {{ color=green; }}	div {{ color: green; }}	Use colon.	CSS
function test(x) print(x) end	function test(x) print(x) end	Correct.	Lua
num = 79	num=79	No spaces.	Shell
bar == '3'	bar === 3	Use strict equality.	JavaScript
def bar(): print('value')	def bar(): print('value')	Indent function body.	Python
def render(a): return a + 1	def render(a): return a + 1	Correct.	Python
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
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 item = 85:	if item == 85:	Use == for comparison.	Python
if item > 45 print('output')	if item > 45: print('output')	Colon missing after if.	Python
{{"value":"data",}}	{{"value":"data"}}	Remove trailing comma.	JSON
local num = 26	local num = 26	Correct.	Lua
if (bar = 52) {{}}	if (bar == 52) {{}}	Use ==.	Kotlin
var index int = 'hello'	var index string = 'hello'	Type mismatch.	Go
let temp: number \| null = null; temp.toFixed(41);	let temp: number \| null = null; if(temp!==null) temp.toFixed(41);	Null check.	TypeScript
class User {{ int bar; }} obj.bar=5;	class User {{ public int bar; }} obj.bar=5;	Make field public.	Java
<table><tr><td>test<td>data</tr></table>	<table><tr><td>test</td><td>data</td></tr></table>	Close td.	HTML
WHERE email = '6'	WHERE email = 6	Don't quote integer.	SQL
list.forEach(function(foo) {{ console.log(foo); }})	list.forEach((foo) => {{ console.log(foo); }})	Arrow functions are cleaner.	JavaScript
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
int[] list = new int[8]; list[8] = 5;	int[] list = new int[8]; if (8 < list.length) list[8] = 5;	Check bounds.	Java
if a = 89 then print('result') end	if a == 89 then print('result') end	Use ==.	Lua
let text1 = String::from("output"); let str2 = text1; println!("{{}}", text1);	let text1 = String::from("output"); let str2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
int arr[7]; arr[7]=5;	int arr[7]; if(7<7){{}} else arr[7]=5;	Bounds check.	C++
System.out.println('message')	System.out.println('message');	Add semicolon.	Java
<?php // code ?>	<?php // code ?>	Correct.	PHP
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
int* p = nullptr; *p=5;	int* p = new int; *p=5;	Allocate memory.	C++
let msg = String::from("data"); let ref=&msg; msg.push_str("!");	let mut msg = String::from("data"); let ref=&msg; println!("{{}}", ref); msg.push_str("!");	Cannot mutate while borrowed.	Rust
let val = 36; let val = 39;	let val = 36; val = 39;	Duplicate declaration.	JavaScript
DELETE FROM items WHERE status=58	DELETE FROM items WHERE status=58;	Add semicolon.	SQL
{{"status":"result" "status":28}}	{{"status":"result", "status":28}}	Add comma.	JSON
json.sqrt(61)	import json json.sqrt(61)	Import module first.	Python
<person age=42>	<person age="42">	Quote attribute.	XML
print 'value'	print 'value';	Add semicolon.	Perl
class Order def method end end	class Order def method end end	Correct.	Ruby
if (x = 20) {{}}	if (x == 20) {{}}	Use ==.	Java
for (data in list)	for (data of list)	for...in iterates keys.	JavaScript
const bar;	const bar = 15;	Initialize const.	JavaScript
class = 'hello'	class_name = 'hello'	'class' is a keyword.	Python
disp('result')	disp('result')	Correct.	MATLAB
if ($val = 52)	if ($val == 52)	Use ==.	Perl
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
Write-Host 'data'	Write-Host 'data'	Correct.	PowerShell
echo 'value'	echo 'value';	Add semicolon.	PHP
fn baz() -> i32 {{ 36 }}	fn baz() -> i32 {{ 36 }}	Correct.	Rust
let x = 13; x += 1;	let mut x = 13; x += 1;	Need mut to modify.	Rust
p {{ color: red }}	p {{ color: red; }}	Add semicolon.	CSS
const bar = 86; bar = 17;	let bar = 86; bar = 17;	Cannot reassign const.	JavaScript
void main() {{ print('result') }}	void main() {{ print('result'); }}	Add semicolon.	Dart
class Person {{ int item; }};	class Person {{ public: int item; }};	Make public.	C++
Post.save();	Post.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
var x = 61;	var x = 61;	Correct.	Dart
[93, 4, 38	[93, 4, 38]	Close bracket.	Ruby
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
console.log('message'	console.log('message')	Close parenthesis.	JavaScript
print('message')	print('message')	Correct.	R
x := 21	x := 21	Correct.	Go
SELECT * FROM orders WHRE id=51;	SELECT * FROM orders WHERE id=51;	Fix WHERE.	SQL
$list[94] = 5;	if (isset($list[94])) $list[94] = 5;	Check existence.	PHP
let c: Int = 'info'	let c: String = 'info'	Fix type.	Swift
let v=vec![81,78,49]; let first=&v[0]; v.push(74);	let mut v=vec![81,78,49]; let first=v[0]; v.push(74);	Copy instead of reference.	Rust
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
if (index) console.log('yes') else console.log('no')	if (index) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
// comment	/* comment */	Use /* */.	CSS
print 'output'	print('output')	print needs parentheses.	Python
<input type='text' value='result'>	<input type='text' value='result' name='name'>	Add name attribute.	HTML
object Product {{ def main(args: Array[String]) = println("output") }}	object Product {{ def main(args: Array[String]): Unit = println("output") }}	Add return type Unit.	Scala
["output", 91]	["output", 91]	Correct.	JSON
while x > 89 x -= 1	while x > 89: x -= 1	Colon missing after while.	Python
print 'hello'	print('hello')	Parentheses for function call.	Lua
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
int index = 'result';	String index = 'result';	Type mismatch.	Dart
String a = 'world';	String a = "world";	Double quotes.	Java
name: data id: hello,	name: data id: hello	Remove comma.	YAML
assert item > 45	assert item > 45	Correct.	Python
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
'info' + 58	'info' + 58.to_s	Convert int.	Ruby
handle	handle()	Add parentheses.	Swift
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
<ul><li>world<li>test</ul>	<ul><li>world</li><li>test</li></ul>	Close li.	HTML
$b = 38; if ($b = 38) {{}}	$b = 38; if ($b == 38) {{}}	Use ==.	PHP
name: value age: 34	name: value age: 34	Correct.	YAML
val count = 'value'	val count = "value"	Double quotes.	Kotlin
val c: Int = 'data'	val c: String = 'data'	Fix type.	Kotlin
<user name='hello'/>	<user name="hello"/>	Double quotes.	XML
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
if (c = 85) {{}}	if (c === 85) {{}}	Use === for equality.	JavaScript
<note><desc>value</desc><name>2</name></note	<note><desc>value</desc><name>2</name></note>	Add closing >.	XML
match x {{ 1 => {{}} }}	match x {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
let count: number = 'data';	let count: string = 'data';	Fix type.	TypeScript
'message' + 55	'message' + str(55)	Can't add int to string.	Python

JOIN orders ON products.id = orders.id

Correct.

SQL

val data = 'message'

val data = "message"

Double quotes.

Kotlin

int data = 'info';

String data = 'info';

Type mismatch.

Dart

'hello' + 99

'hello' + 99.to_s

Convert int.

Ruby

for i=1,28 do print(i) end

Correct.

Lua

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

div {{ color=green; }}

div {{ color: green; }}

Use colon.

CSS

function test(x) print(x) end

Correct.

Lua

num = 79

num=79

No spaces.

Shell

bar == '3'

bar === 3

Use strict equality.

JavaScript

def bar(): print('value')

Indent function body.

Python

def render(a): return a + 1

Correct.

Python

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

Correct.

MATLAB

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 item = 85:

if item == 85:

Use == for comparison.

Python

if item > 45 print('output')

if item > 45: print('output')

Colon missing after if.

Python

Remove trailing comma.

JSON

local num = 26

Correct.

Lua

if (bar = 52) {{}}

if (bar == 52) {{}}

Use ==.

Kotlin

var index int = 'hello'

var index string = 'hello'

Type mismatch.

Go

let temp: number | null = null; temp.toFixed(41);

let temp: number | null = null; if(temp!==null) temp.toFixed(41);

Null check.

TypeScript

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

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

Make field public.

Java

Close td.

HTML

WHERE email = '6'

WHERE email = 6

Don't quote integer.

SQL

list.forEach(function(foo) {{ console.log(foo); }})

list.forEach((foo) => {{ console.log(foo); }})

Arrow functions are cleaner.

JavaScript

lambda x: x+1

Correct lambda.

Python

int[] list = new int[8]; list[8] = 5;

int[] list = new int[8]; if (8 < list.length) list[8] = 5;

Check bounds.

Java

if a = 89 then print('result') end

if a == 89 then print('result') end

Use ==.

Lua

let text1 = String::from("output"); let str2 = text1; println!("{{}}", text1);

let text1 = String::from("output"); let str2 = text1.clone(); println!("{{}}", text1);

Clone to avoid move.

Rust

int arr[7]; arr[7]=5;

int arr[7]; if(7<7){{}} else arr[7]=5;

Bounds check.

C++

System.out.println('message')

System.out.println('message');

Add semicolon.

Java

<?php // code ?>

Correct.

PHP

Correct.

XML

int* p = nullptr; *p=5;

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

Allocate memory.

C++

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

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

Cannot mutate while borrowed.

Rust

let val = 36; let val = 39;

let val = 36; val = 39;

Duplicate declaration.

JavaScript

DELETE FROM items WHERE status=58

DELETE FROM items WHERE status=58;

Add semicolon.

SQL

Add comma.

JSON

json.sqrt(61)

import json json.sqrt(61)

Import module first.

Python

Quote attribute.

XML

print 'value'

print 'value';

Add semicolon.

Perl

class Order def method end end

Correct.

Ruby

if (x = 20) {{}}

if (x == 20) {{}}

Use ==.

Java

for (data in list)

for (data of list)

for...in iterates keys.

JavaScript

const bar;

const bar = 15;

Initialize const.

JavaScript

class = 'hello'

class_name = 'hello'

'class' is a keyword.

Python

disp('result')

Correct.

MATLAB

if ($val = 52)

if ($val == 52)

Use ==.

Perl

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

Write-Host 'data'

Correct.

PowerShell

echo 'value'

echo 'value';

Add semicolon.

PHP

fn baz() -> i32 {{ 36 }}

Correct.

Rust

let x = 13; x += 1;

let mut x = 13; x += 1;

Need mut to modify.

Rust

p {{ color: red }}

p {{ color: red; }}

Add semicolon.

CSS

const bar = 86; bar = 17;

let bar = 86; bar = 17;

Cannot reassign const.

JavaScript

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

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

Add semicolon.

Dart

class Person {{ int item; }};

class Person {{ public: int item; }};

Make public.

C++

Post.save();

Post.save().then(()=>{{}}).catch(err=>{{}});

Handle promise.

Node.js

var x = 61;

Correct.

Dart

[93, 4, 38

[93, 4, 38]

Close bracket.

Ruby

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

console.log('message'

console.log('message')

Close parenthesis.

JavaScript

print('message')

Correct.

R

x := 21

Correct.

Go

SELECT * FROM orders WHRE id=51;

SELECT * FROM orders WHERE id=51;

Fix WHERE.

SQL

$list[94] = 5;

if (isset($list[94])) $list[94] = 5;

Check existence.

PHP

let c: Int = 'info'

let c: String = 'info'

Fix type.

Swift

let v=vec![81,78,49]; let first=&v[0]; v.push(74);

let mut v=vec![81,78,49]; let first=v[0]; v.push(74);

Copy instead of reference.

Rust

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

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

Type not in union.

TypeScript

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

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

Missing semicolon.

JavaScript

// comment

/* comment */

Use /* */.

CSS

print 'output'

print('output')

print needs parentheses.

Python

Add name attribute.

HTML

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

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

Add return type Unit.

Scala

["output", 91]

Correct.

JSON

while x > 89 x -= 1

while x > 89: x -= 1

Colon missing after while.

Python

print 'hello'

print('hello')

Parentheses for function call.

Lua

int main() {{ return 0; }}

Correct.

C++

int index = 'result';

String index = 'result';

Type mismatch.

Dart

String a = 'world';

String a = "world";

Double quotes.

Java

Remove comma.

YAML

assert item > 45

Correct.

Python

package main func main() {{}}

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

Import needed.

Go

'info' + 58

'info' + 58.to_s

Convert int.

Ruby

handle

handle()

Add parentheses.

Swift

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

<ul><li>world<li>test</ul>

<ul><li>world</li><li>test</li></ul>

Close li.

HTML

$b = 38; if ($b = 38) {{}}

$b = 38; if ($b == 38) {{}}

Use ==.

PHP

Correct.

YAML

val count = 'value'

val count = "value"

Double quotes.

Kotlin

val c: Int = 'data'

val c: String = 'data'

Fix type.

Kotlin

Double quotes.

XML

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

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

Correct.

Shell

if (c = 85) {{}}

if (c === 85) {{}}

Use === for equality.

JavaScript

<note><desc>value</desc><name>2</name></note

<note><desc>value</desc><name>2</name></note>

Add closing >.

XML

match x {{ 1 => {{}} }}

match x {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

let count: number = 'data';

let count: string = 'data';

Fix type.

TypeScript

'message' + 55

'message' + str(55)

Can't add int to string.

Python