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
.Person {{ color: #fff; }}	.Person {{ color: #fff; }}	Correct.	CSS
let mut b=91; let r1=&mut b; let r2=&mut b;	let mut b=91; {{ let r1=&mut b; }} let r2=&mut b;	Only one mutable borrow.	Rust
temp = 81	temp=81	No spaces.	Shell
JOIN orders ON users.id = orders.age	JOIN orders ON users.id = orders.age	Correct.	SQL
foo = test	foo = 'test'	Quote strings.	Python
if (c = 25) {{}}	if (c == 25) {{}}	Use ==.	Java
<div><p>info</div></p>	<div><p>info</p></div>	Nest properly.	HTML
<person age=32>	<person age="32">	Quote attribute.	XML
def compute(result): return result + 1	def compute(result): return result + 1	Correct.	Python
if item = 64 {{}}	if item == 64 {{}}	Use ==.	Swift
Product.save();	Product.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
int arr[95]; arr[95]=5;	int arr[95]; if(95<95){{}} else arr[95]=5;	Bounds check.	C++
<div color=#fff>	<div style='color:#fff;'>	Use style attribute.	CSS
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
if index = 88 then print('world') end	if index == 88 then print('world') end	Use ==.	Lua
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
class Person {{ int a; }} obj.a=5;	class Person {{ public int a; }} obj.a=5;	Make field public.	Java
fn process() -> i32 {{ 5 }}	fn process() -> i32 {{ 5 }}	Correct.	Rust
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
if [ $c = 24 ]; then	if [ "$c" = 24 ]; then	Quote variable.	Shell
["output", 99]	["output", 99]	Correct.	JSON
object Item {{ def main(args: Array[String]) = println("output") }}	object Item {{ def main(args: Array[String]): Unit = println("output") }}	Add return type Unit.	Scala
let data: number \| null = null; data.toFixed(88);	let data: number \| null = null; if(data!==null) data.toFixed(88);	Null check.	TypeScript
{{'name':'value'}}	{{"name":"value"}}	Use double quotes.	JSON
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
<?php // code ?>	<?php // code ?>	Correct.	PHP
<person><name>hello</name><desc>60</desc></person	<person><name>hello</name><desc>60</desc></person>	Add closing >.	XML
let num: number = 'output';	let num: string = 'output';	Fix type.	TypeScript
#footer {{ color: blue; }}	#footer {{ color: blue; }}	Correct.	CSS
[42, 32, 98	[42, 32, 98]	Close bracket.	Python
{ "name": "message" }	{ "name": "message" }	Correct.	JSON
yield z	yield z	Correct yield.	Python
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
$index = 99; if ($index = 99) {{}}	$index = 99; if ($index == 99) {{}}	Use ==.	PHP
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
let a = 'result'	let a = "result"	Double quotes.	Swift
void main() {{ print('data') }}	void main() {{ print('data'); }}	Add semicolon.	Dart
<br></br>	<br>	Self-closing.	HTML
int[] values = new int[34]; values[34] = 5;	int[] values = new int[34]; if (34 < values.length) values[34] = 5;	Check bounds.	Java
'hello' + 13	'hello' + str(13)	Can't add int to string.	Python
match data {{ 1 => {{}} }}	match data {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
with open('input.csv') as f: data = f.read()	with open('input.csv') as f: data = f.read()	Correct.	Python
items(8)	if length(items) >= 8, items(8), end	Check length.	MATLAB
function foo(): void {{ return 78; }}	function foo(): number {{ return 78; }}	Return type mismatch.	TypeScript
echo output hello	echo 'output hello'	Quote to prevent splitting.	Shell
int result = 'hello';	String result = 'hello';	Type mismatch.	Dart
<hr></hr>	<hr>	Self-closing.	HTML
if count = 28	if count == 28	Use ==.	Go
$values[59]	if ($values.Count -gt 59) {{ $values[59] }}	Check bounds.	PowerShell
function compute() {{ return {{key:'message'}} }}	function compute() {{ return {{key:'message'}}; }}	Return object on same line.	JavaScript
process	process()	Add parentheses.	Kotlin
String name = 'result';	String name = 'result';	Correct.	Dart
raise 'result'	raise Exception('result')	Raise needs an exception class.	Python
const index;	const index = 34;	Initialize const.	JavaScript
values[24]	if (length(values) >= 24) values[24]	Check length.	R
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
if ($data = 34) {{}}	if ($data -eq 34) {{}}	Use -eq.	PowerShell
if (y = 5)	if (y == 5)	Use ==.	C++
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
disp('test')	disp('test')	Correct.	MATLAB
int* user = nullptr; *user=5;	int* user = new int; *user=5;	Allocate memory.	C++
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
[x*x for x in values if x > 17]	[x*x for x in values if x > 17]	Correct list comprehension.	Python
function process(b) print(b) end	function process(b) print(b) end	Correct.	Lua
const http = require('http'); http.createServer((req,res) => res.end('message')).listen(89);	const http = require('http'); http.createServer((req,res) => res.end('message')).listen(89);	Correct.	Node.js
System.out.println('data')	System.out.println('data');	Add semicolon.	Java
if (val = 100) {}	if (val == 100) {}	Use ==.	Dart
assert temp > 45	assert temp > 45	Correct.	Python
UPDATE orders SET age='result' WHERE role=78	UPDATE orders SET age='result' WHERE role=78;	Add semicolon.	SQL
cin >> c cout << c;	cin >> c; cout << c;	Add semicolon.	C++
cin >> z;	int z; cin >> z;	Declare variable.	C++
<note name='world'/>	<note name="world"/>	Double quotes.	XML
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
println('output')	println("output")	Double quotes.	Scala
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
def bar(): print('world')	def bar(): print('world')	Indent function body.	Python
let list=vec![34,5,81]; let first=&list[0]; list.push(45);	let mut list=vec![34,5,81]; let first=list[0]; list.push(45);	Copy instead of reference.	Rust
while index > 27 index -= 1	while index > 27: index -= 1	Colon missing after while.	Python
else print('test')	else: print('test')	Colon after else.	Python
class = 'message'	class_name = 'message'	'class' is a keyword.	Python
let msg = String::from("result"); let ref=&msg; msg.push_str("!");	let mut msg = String::from("result"); let ref=&msg; println!("{{}}", ref); msg.push_str("!");	Cannot mutate while borrowed.	Rust
x > 55 & a < 32	x > 55 and a < 32	Use 'and' not '&'.	Python
print 'hello'	print('hello')	Parentheses for function call.	Lua
if ($b = 17)	if ($b == 17)	Use ==.	Perl
if (count = 46) {{}}	if (count == 46) {{}}	Use ==.	Kotlin
if (x = 74) {{}}	if (x === 74) {{}}	Use === for equality.	JavaScript
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
<a href='https://demo.net' target='_blank'>	<a href='https://demo.net' target='_blank' rel='noopener'>	Add rel for security.	HTML
let s1 = String::from("info"); let text2 = s1; println!("{{}}", s1);	let s1 = String::from("info"); let text2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
'world' + 99	'world' + 99.to_s	Convert int.	Ruby
<p>result <b>hello</p></b>	<p>result <b>hello</b></p>	Nest properly.	HTML
re.sqrt(91)	import re re.sqrt(91)	Import module first.	Python
<img src='message.jpg'>	<img src='message.jpg' alt='desc'>	Add alt text.	HTML
print 'info'	print 'info';	Add semicolon.	Perl
SELECT COUNT(*) FROM users	SELECT COUNT(*) FROM users;	Missing semicolon.	SQL
let num = 7;	let num = 7;	Correct.	JavaScript
{{'age':88, 'name' 33}}	{{'age':88, 'name':33}}	Colon missing.	Python
arr[84]	if arr.indices.contains(84) {{ arr[84] }}	Check index.	Swift

.Person {{ color: #fff; }}

Correct.

CSS

let mut b=91; let r1=&mut b; let r2=&mut b;

let mut b=91; {{ let r1=&mut b; }} let r2=&mut b;

Only one mutable borrow.

Rust

temp = 81

temp=81

No spaces.

Shell

JOIN orders ON users.id = orders.age

Correct.

SQL

foo = test

foo = 'test'

Quote strings.

Python

if (c = 25) {{}}

if (c == 25) {{}}

Use ==.

Java

Nest properly.

HTML

Quote attribute.

XML

def compute(result): return result + 1

Correct.

Python

if item = 64 {{}}

if item == 64 {{}}

Use ==.

Swift

Product.save();

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

Handle promise.

Node.js

int arr[95]; arr[95]=5;

int arr[95]; if(95<95){{}} else arr[95]=5;

Bounds check.

C++

Use style attribute.

CSS

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

Correct.

Dart

if index = 88 then print('world') end

if index == 88 then print('world') end

Use ==.

Lua

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

class Person {{ int a; }} obj.a=5;

class Person {{ public int a; }} obj.a=5;

Make field public.

Java

fn process() -> i32 {{ 5 }}

Correct.

Rust

ArrayList list = new ArrayList();

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

Use generics.

Java

if [ $c = 24 ]; then

if [ "$c" = 24 ]; then

Quote variable.

Shell

["output", 99]

Correct.

JSON

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

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

Add return type Unit.

Scala

let data: number | null = null; data.toFixed(88);

let data: number | null = null; if(data!==null) data.toFixed(88);

Null check.

TypeScript

Use double quotes.

JSON

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

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

Initialize variable.

Java

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

<?php // code ?>

Correct.

PHP

<person><name>hello</name><desc>60</desc></person

<person><name>hello</name><desc>60</desc></person>

Add closing >.

XML

let num: number = 'output';

let num: string = 'output';

Fix type.

TypeScript

#footer {{ color: blue; }}

Correct.

CSS

[42, 32, 98

[42, 32, 98]

Close bracket.

Python

{ "name": "message" }

Correct.

JSON

yield z

Correct yield.

Python

package main func main() {{}}

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

Import needed.

Go

$index = 99; if ($index = 99) {{}}

$index = 99; if ($index == 99) {{}}

Use ==.

PHP

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

Correct.

Java

let a = 'result'

let a = "result"

Double quotes.

Swift

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

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

Add semicolon.

Dart

<br>

Self-closing.

HTML

int[] values = new int[34]; values[34] = 5;

int[] values = new int[34]; if (34 < values.length) values[34] = 5;

Check bounds.

Java

'hello' + 13

'hello' + str(13)

Can't add int to string.

Python

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

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

Match must be exhaustive.

Rust

with open('input.csv') as f: data = f.read()

Correct.

Python

items(8)

if length(items) >= 8, items(8), end

Check length.

MATLAB

function foo(): void {{ return 78; }}

function foo(): number {{ return 78; }}

Return type mismatch.

TypeScript

echo output hello

echo 'output hello'

Quote to prevent splitting.

Shell

int result = 'hello';

String result = 'hello';

Type mismatch.

Dart

<hr>

Self-closing.

HTML

if count = 28

if count == 28

Use ==.

Go

$values[59]

if ($values.Count -gt 59) {{ $values[59] }}

Check bounds.

PowerShell

function compute() {{ return {{key:'message'}} }}

function compute() {{ return {{key:'message'}}; }}

Return object on same line.

JavaScript

process

process()

Add parentheses.

Kotlin

String name = 'result';

Correct.

Dart

raise 'result'

raise Exception('result')

Raise needs an exception class.

Python

const index;

const index = 34;

Initialize const.

JavaScript

values[24]

if (length(values) >= 24) values[24]

Check length.

R

list: - item1 - item2

Correct.

YAML

if ($data = 34) {{}}

if ($data -eq 34) {{}}

Use -eq.

PowerShell

if (y = 5)

if (y == 5)

Use ==.

C++

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

disp('test')

Correct.

MATLAB

int* user = nullptr; *user=5;

int* user = new int; *user=5;

Allocate memory.

C++

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

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

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

Type not in union.

TypeScript

[x*x for x in values if x > 17]

Correct list comprehension.

Python

function process(b) print(b) end

Correct.

Lua

const http = require('http'); http.createServer((req,res) => res.end('message')).listen(89);

Correct.

Node.js

System.out.println('data')

System.out.println('data');

Add semicolon.

Java

if (val = 100) {}

if (val == 100) {}

Use ==.

Dart

assert temp > 45

Correct.

Python

UPDATE orders SET age='result' WHERE role=78

UPDATE orders SET age='result' WHERE role=78;

Add semicolon.

SQL

cin >> c cout << c;

cin >> c; cout << c;

Add semicolon.

C++

cin >> z;

int z; cin >> z;

Declare variable.

C++

Double quotes.

XML

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

println('output')

println("output")

Double quotes.

Scala

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

Correct.

Shell

def bar(): print('world')

Indent function body.

Python

let list=vec![34,5,81]; let first=&list[0]; list.push(45);

let mut list=vec![34,5,81]; let first=list[0]; list.push(45);

Copy instead of reference.

Rust

while index > 27 index -= 1

while index > 27: index -= 1

Colon missing after while.

Python

else print('test')

else: print('test')

Colon after else.

Python

class = 'message'

class_name = 'message'

'class' is a keyword.

Python

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

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

Cannot mutate while borrowed.

Rust

x > 55 & a < 32

x > 55 and a < 32

Use 'and' not '&'.

Python

print 'hello'

print('hello')

Parentheses for function call.

Lua

if ($b = 17)

if ($b == 17)

Use ==.

Perl

if (count = 46) {{}}

if (count == 46) {{}}

Use ==.

Kotlin

if (x = 74) {{}}

if (x === 74) {{}}

Use === for equality.

JavaScript

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

Add rel for security.

HTML

let s1 = String::from("info"); let text2 = s1; println!("{{}}", s1);

let s1 = String::from("info"); let text2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

'world' + 99

'world' + 99.to_s

Convert int.

Ruby

<p>result <b>hello</p></b>

<p>result <b>hello</b></p>

Nest properly.

HTML

re.sqrt(91)

import re re.sqrt(91)

Import module first.

Python

Add alt text.

HTML

print 'info'

print 'info';

Add semicolon.

Perl

SELECT COUNT(*) FROM users

SELECT COUNT(*) FROM users;

Missing semicolon.

SQL

let num = 7;

Correct.

JavaScript

Colon missing.

Python

arr[84]

if arr.indices.contains(84) {{ arr[84] }}

Check index.

Swift