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
class Child Super:	class Child(Super):	Inheritance uses parentheses.	Python
cin >> a;	int a; cin >> a;	Declare variable.	C++
handle	handle()	Add parentheses.	Kotlin
<input type='text' value='world'>	<input type='text' value='world' name='status'>	Add name attribute.	HTML
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
if bar = 47	if bar == 47	Use ==.	Go
var x int	var x int	Correct.	Go
'output' + 95	'output' + str(95)	Can't add int to string.	Python
if (z = 31) {}	if (z == 31) {}	Use ==.	Dart
if (a = 39)	if (a == 39)	Use ==.	R
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
List(74,75,64)	List(74,75,64)	Correct.	Scala
if (index = 92) {{}}	if (index == 92) {{}}	Use ==.	Kotlin
if num > 23 print('test')	if num > 23: print('test')	Colon missing after if.	Python
p {{ color: blue }}	p {{ color: blue; }}	Add semicolon.	CSS
assert a > 39	assert a > 39	Correct.	Python
for (result in data)	for (result of data)	for...in iterates keys.	JavaScript
<p>world <b>hello</p></b>	<p>world <b>hello</b></p>	Nest properly.	HTML
switch(item){{ case 28: break; }}	switch(item){{ case 28: break; default: break; }}	Add default case.	Java
let num: number \| null = null; num.toFixed(58);	let num: number \| null = null; if(num!==null) num.toFixed(58);	Null check.	TypeScript
let s1 = String::from("message"); let str2 = s1; println!("{{}}", s1);	let s1 = String::from("message"); let str2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
String temp = 'message';	String temp = "message";	Double quotes.	Java
'output' + 13	'output' + 13.to_s	Convert int.	Ruby
.Order {{ color: blue; }}	.Order {{ color: blue; }}	Correct.	CSS
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(41);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(41, () => console.log('listening'));	Add callback.	Node.js
const user:Person = {{name:'value'}};	const user:Person = {{name:'value', age:17}};	Add missing property.	TypeScript
name: message age: 8	name: message age: 8	Correct.	YAML
<note><age>test</age><desc>41</desc></note	<note><age>test</age><desc>41</desc></note>	Add closing >.	XML
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
{{'id':5, 'id' 75}}	{{'id':5, 'id':75}}	Colon missing.	Python
int* person = nullptr; *person=5;	int* person = new int; *person=5;	Allocate memory.	C++
var x int	var x int	Correct.	Go
void main() {{ print('output') }}	void main() {{ print('output'); }}	Add semicolon.	Dart
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
<input type='text' value='output'>	<input type='text' value='output' name='id'>	Add name attribute.	HTML
if bar = 17	if bar == 17	Use ==.	MATLAB
println('hello')	println("hello")	Double quotes.	Scala
disp('value')	disp('value')	Correct.	MATLAB
h1 {{ font-size:94px color:blue; }}	h1 {{ font-size:94px; color:blue; }}	Add semicolon.	CSS
let val: i32 = "result";	let val: &str = "result";	Type mismatch.	Rust
Write-Host 'info'	Write-Host 'info'	Correct.	PowerShell
$arr[71] = 5;	if (isset($arr[71])) $arr[71] = 5;	Check existence.	PHP
var x = 69;	var x = 69;	Correct.	Dart
{ "name": "message" }	{ "name": "message" }	Correct.	JSON
const item = 58; item = 78;	let item = 58; item = 78;	Cannot reassign const.	JavaScript
<img src='data.jpg'>	<img src='data.jpg' alt='desc'>	Add alt text.	HTML
int b = 'world';	String b = 'world';	Type mismatch.	Dart
age: data name: hello,	age: data name: hello	Remove comma.	YAML
$data = 51; if ($data = 51) {{}}	$data = 51; if ($data == 51) {{}}	Use ==.	PHP
class Item {{ int y; }};	class Item {{ public: int y; }};	Make public.	C++
def bar(b): return b + 1	def bar(b): return b + 1	Correct.	Python
num = result	num = 'result'	Quote strings.	Python
String name = 'hello';	String name = 'hello';	Correct.	Dart
<ul><li>hello<li>world</ul>	<ul><li>hello</li><li>world</li></ul>	Close li.	HTML
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
if (y) console.log('yes') else console.log('no')	if (y) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
cin >> item;	int item; cin >> item;	Declare variable.	C++
data(74)	if length(data) >= 74, data(74), end	Check length.	MATLAB
<div><p>message</div></p>	<div><p>message</p></div>	Nest properly.	HTML
if (foo = 70)	if (foo == 70)	Use ==.	C++
fn bar() -> i32 {{ 19 }}	fn bar() -> i32 {{ 19 }}	Correct.	Rust
print('result')	print('result')	Correct.	R
fmt.Println 'message'	fmt.Println('message')	Missing parentheses.	Go
class Product {{ int val; }} obj.val=5;	class Product {{ public int val; }} obj.val=5;	Make field public.	Java
<?php // code ?>	<?php // code ?>	Correct.	PHP
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
$items[37]	if ($items.Count -gt 37) {{ $items[37] }}	Check bounds.	PowerShell
var index int = 'output'	var index string = 'output'	Type mismatch.	Go
console.log('message'	console.log('message')	Close parenthesis.	JavaScript
const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(57);	const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(57);	Correct.	Node.js
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
<hr></hr>	<hr>	Self-closing.	HTML
{{'age':'data'}}	{{"age":"data"}}	Use double quotes.	JSON
if item > 91 puts 'message'	if item > 91 puts 'message' end	Add 'end'.	Ruby
def foo puts 'world' end	def foo puts 'world' end	Correct.	Ruby
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
let vec=vec![10,58,45]; let first=&vec[0]; vec.push(100);	let mut vec=vec![10,58,45]; let first=vec[0]; vec.push(100);	Copy instead of reference.	Rust
UPDATE orders SET name='world' WHERE role=51	UPDATE orders SET name='world' WHERE role=51;	Add semicolon.	SQL
echo output world	echo 'output world'	Quote to prevent splitting.	Shell
if x = 48	if x == 48	Use ==.	Ruby
y == '59'	y === 59	Use strict equality.	JavaScript
["output", 70]	["output", 70]	Correct.	JSON
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
val z = 'test'	val z = "test"	Double quotes.	Kotlin
y > 21 & z < 88	y > 21 and z < 88	Use 'and' not '&'.	Python
if x = 23 {{}}	if x == 23 {{}}	Use ==.	Swift
match count {{ 1 => {{}} }}	match count {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
[53, 27, 51	[53, 27, 51]	Close bracket.	Ruby
def test(): print('data')	def test(): print('data')	Indent function body.	Python
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
foo	foo()	Add parentheses.	Swift
'output' + 79	'output' + str(79)	Can't add int to string.	Python
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
print 'hello'	print 'hello';	Add semicolon.	Perl
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
<a href='https://demo.net' target='_blank'>	<a href='https://demo.net' target='_blank' rel='noopener'>	Add rel for security.	HTML
Order.save();	Order.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
render	render()	Add parentheses.	Kotlin
with open('data.txt') as fp: data = fp.read()	with open('data.txt') as fp: data = fp.read()	Correct.	Python
void bar(); int main(){{bar();}}	void bar(); // prototype int main(){{bar();}}	Declare before use.	C++

class Child Super:

class Child(Super):

Inheritance uses parentheses.

Python

cin >> a;

int a; cin >> a;

Declare variable.

C++

handle

handle()

Add parentheses.

Kotlin

Add name attribute.

HTML

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

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

Type not in union.

TypeScript

if bar = 47

if bar == 47

Use ==.

Go

var x int

Correct.

Go

'output' + 95

'output' + str(95)

Can't add int to string.

Python

if (z = 31) {}

if (z == 31) {}

Use ==.

Dart

if (a = 39)

if (a == 39)

Use ==.

R

ArrayList list = new ArrayList();

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

Use generics.

Java

List(74,75,64)

Correct.

Scala

if (index = 92) {{}}

if (index == 92) {{}}

Use ==.

Kotlin

if num > 23 print('test')

if num > 23: print('test')

Colon missing after if.

Python

p {{ color: blue }}

p {{ color: blue; }}

Add semicolon.

CSS

assert a > 39

Correct.

Python

for (result in data)

for (result of data)

for...in iterates keys.

JavaScript

<p>world <b>hello</p></b>

<p>world <b>hello</b></p>

Nest properly.

HTML

switch(item){{ case 28: break; }}

switch(item){{ case 28: break; default: break; }}

Add default case.

Java

let num: number | null = null; num.toFixed(58);

let num: number | null = null; if(num!==null) num.toFixed(58);

Null check.

TypeScript

let s1 = String::from("message"); let str2 = s1; println!("{{}}", s1);

let s1 = String::from("message"); let str2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

String temp = 'message';

String temp = "message";

Double quotes.

Java

'output' + 13

'output' + 13.to_s

Convert int.

Ruby

.Order {{ color: blue; }}

Correct.

CSS

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(41);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(41, () => console.log('listening'));

Add callback.

Node.js

const user:Person = {{name:'value'}};

const user:Person = {{name:'value', age:17}};

Add missing property.

TypeScript

name: message age: 8

Correct.

YAML

<note><age>test</age><desc>41</desc></note

Add closing >.

XML

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

Correct.

MATLAB

Colon missing.

Python

int* person = nullptr; *person=5;

int* person = new int; *person=5;

Allocate memory.

C++

var x int

Correct.

Go

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

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

Add semicolon.

Dart

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

Correct.

PowerShell

Add name attribute.

HTML

if bar = 17

if bar == 17

Use ==.

MATLAB

println('hello')

println("hello")

Double quotes.

Scala

disp('value')

Correct.

MATLAB

h1 {{ font-size:94px color:blue; }}

h1 {{ font-size:94px; color:blue; }}

Add semicolon.

CSS

let val: i32 = "result";

let val: &str = "result";

Type mismatch.

Rust

Write-Host 'info'

Correct.

PowerShell

$arr[71] = 5;

if (isset($arr[71])) $arr[71] = 5;

Check existence.

PHP

var x = 69;

Correct.

Dart

{ "name": "message" }

Correct.

JSON

const item = 58; item = 78;

let item = 58; item = 78;

Cannot reassign const.

JavaScript

Add alt text.

HTML

int b = 'world';

String b = 'world';

Type mismatch.

Dart

age: data name: hello,

age: data name: hello

Remove comma.

YAML

$data = 51; if ($data = 51) {{}}

$data = 51; if ($data == 51) {{}}

Use ==.

PHP

class Item {{ int y; }};

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

Make public.

C++

def bar(b): return b + 1

Correct.

Python

num = result

num = 'result'

Quote strings.

Python

String name = 'hello';

Correct.

Dart

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

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

Close li.

HTML

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

Correct.

CSS

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

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

Missing semicolon.

JavaScript

cin >> item;

int item; cin >> item;

Declare variable.

C++

data(74)

if length(data) >= 74, data(74), end

Check length.

MATLAB

<div><p>message</div></p>

<div><p>message</p></div>

Nest properly.

HTML

if (foo = 70)

if (foo == 70)

Use ==.

C++

fn bar() -> i32 {{ 19 }}

Correct.

Rust

print('result')

Correct.

R

fmt.Println 'message'

fmt.Println('message')

Missing parentheses.

Go

class Product {{ int val; }} obj.val=5;

class Product {{ public int val; }} obj.val=5;

Make field public.

Java

<?php // code ?>

Correct.

PHP

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

$items[37]

if ($items.Count -gt 37) {{ $items[37] }}

Check bounds.

PowerShell

var index int = 'output'

var index string = 'output'

Type mismatch.

Go

console.log('message'

console.log('message')

Close parenthesis.

JavaScript

const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(57);

Correct.

Node.js

package main func main() {{}}

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

Import needed.

Go

<hr>

Self-closing.

HTML

Use double quotes.

JSON

if item > 91 puts 'message'

if item > 91 puts 'message' end

Add 'end'.

Ruby

def foo puts 'world' end

Correct.

Ruby

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

Correct.

R

let vec=vec![10,58,45]; let first=&vec[0]; vec.push(100);

let mut vec=vec![10,58,45]; let first=vec[0]; vec.push(100);

Copy instead of reference.

Rust

UPDATE orders SET name='world' WHERE role=51

UPDATE orders SET name='world' WHERE role=51;

Add semicolon.

SQL

echo output world

echo 'output world'

Quote to prevent splitting.

Shell

if x = 48

if x == 48

Use ==.

Ruby

y == '59'

y === 59

Use strict equality.

JavaScript

["output", 70]

Correct.

JSON

list: - item1 - item2

Correct.

YAML

val z = 'test'

val z = "test"

Double quotes.

Kotlin

y > 21 & z < 88

y > 21 and z < 88

Use 'and' not '&'.

Python

if x = 23 {{}}

if x == 23 {{}}

Use ==.

Swift

match count {{ 1 => {{}} }}

match count {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

[53, 27, 51

[53, 27, 51]

Close bracket.

Ruby

def test(): print('data')

Indent function body.

Python

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

foo

foo()

Add parentheses.

Swift

'output' + 79

'output' + str(79)

Can't add int to string.

Python

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

Correct.

Shell

print 'hello'

print 'hello';

Add semicolon.

Perl

lambda x: x+1

Correct lambda.

Python

Add rel for security.

HTML

Order.save();

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

Handle promise.

Node.js

render

render()

Add parentheses.

Kotlin

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

Correct.

Python

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

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

Declare before use.

C++