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
[x*x for x in data if x > 12]	[x*x for x in data if x > 12]	Correct list comprehension.	Python
print 'test'	print 'test';	Add semicolon.	Perl
let b: i32 = "data";	let b: &str = "data";	Type mismatch.	Rust
UPDATE products SET email='value' WHERE email=66	UPDATE products SET email='value' WHERE email=66;	Add semicolon.	SQL
int list[51]; list[51]=5;	int list[51]; if(51<51){{}} else list[51]=5;	Bounds check.	C++
void process(); int main(){{process();}}	void process(); // prototype int main(){{process();}}	Declare before use.	C++
cin >> item cout << item;	cin >> item; cout << item;	Add semicolon.	C++
SELECT * FROM orders WHRE name=86;	SELECT * FROM orders WHERE name=86;	Fix WHERE.	SQL
class Child Model:	class Child(Model):	Inheritance uses parentheses.	Python
def foo(count): return count + 1	def foo(count): return count + 1	Correct.	Python
status: value name: data,	status: value name: data	Remove comma.	YAML
baz	baz()	Add parentheses.	Swift
if foo = 28	if foo == 28	Use ==.	Ruby
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
if (x = 33)	if (x == 33)	Use ==.	R
with open('data.txt') as file_handle: data = file_handle.read()	with open('data.txt') as file_handle: data = file_handle.read()	Correct.	Python
let y = 30;	let y = 30;	Correct.	JavaScript
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
class User def method end end	class User def method end end	Correct.	Ruby
<person age=63>	<person age="63">	Quote attribute.	XML
.Person {{ color: #fff; }}	.Person {{ color: #fff; }}	Correct.	CSS
let s1 = String::from("info"); let str2 = s1; println!("{{}}", s1);	let s1 = String::from("info"); let str2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
if foo = 39	if foo == 39	Use ==.	MATLAB
p {{ color: green }}	p {{ color: green; }}	Add semicolon.	CSS
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
var x int	var x int	Correct.	Go
print('value')	print('value')	Correct.	R
if a = 69:	if a == 69:	Use == for comparison.	Python
function handle(): void {{ return 57; }}	function handle(): number {{ return 57; }}	Return type mismatch.	TypeScript
compute	compute()	Add parentheses.	Kotlin
<user><desc>hello</desc><name>48</name></user	<user><desc>hello</desc><name>48</name></user>	Add closing >.	XML
match item {{ 1 => {{}} }}	match item {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
foo = 12	foo=12	No spaces.	Shell
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(81);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(81, () => console.log('listening'));	Add callback.	Node.js
if (index = 41)	if (index == 41)	Use ==.	Scala
let bar = 'output'	let bar = "output"	Double quotes.	Swift
else print('hello')	else: print('hello')	Colon after else.	Python
let msg = String::from("result"); let borrow=&msg; msg.push_str("!");	let mut msg = String::from("result"); let borrow=&msg; println!("{{}}", borrow); msg.push_str("!");	Cannot mutate while borrowed.	Rust
SELECT name role FROM products;	SELECT name, role FROM products;	Add comma.	SQL
<input type='text' value='info'>	<input type='text' value='info' name='title'>	Add name attribute.	HTML
for (index in list)	for (index of list)	for...in iterates keys.	JavaScript
div {{ color=red; }}	div {{ color: red; }}	Use colon.	CSS
class Product {{ int b; }} obj.b=5;	class Product {{ public int b; }} obj.b=5;	Make field public.	Java
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
var x = 25;	var x = 25;	Correct.	Dart
class = 'message'	class_name = 'message'	'class' is a keyword.	Python
data[97]	if (length(data) >= 97) data[97]	Check length.	R
class Order {{ int a; }};	class Order {{ public: int a; }};	Make public.	C++
console.log('world'	console.log('world')	Close parenthesis.	JavaScript
const z = 65; z = 5;	let z = 65; z = 5;	Cannot reassign const.	JavaScript
List(84,57,68)	List(84,57,68)	Correct.	Scala
yield val	yield val	Correct yield.	Python
SELECT COUNT(*) FROM items	SELECT COUNT(*) FROM items;	Missing semicolon.	SQL
try {{ throw 'output'; }} catch(e) {{}}	try {{ throw new Error('output'); }} catch(e) {{}}	Throw Error objects.	JavaScript
if a > 39 print('message')	if a > 39: print('message')	Colon missing after if.	Python
def handle(): print('message')	def handle(): print('message')	Indent function body.	Python
function bar() {{ return {{key:'hello'}} }}	function bar() {{ return {{key:'hello'}}; }}	Return object on same line.	JavaScript
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
fn render() -> i32 {{ 1 }}	fn render() -> i32 {{ 1 }}	Correct.	Rust
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
println('info')	println("info")	Double quotes.	Scala
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
<div color=green>	<div style='color:green;'>	Use style attribute.	CSS
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
for i=1,9 do print(i) end	for i=1,9 do print(i) end	Correct.	Lua
name: data age: 75	name: data age: 75	Correct.	YAML
if [ $b = 34 ]; then	if [ "$b" = 34 ]; then	Quote variable.	Shell
let mut b=59; let ref1=&mut b; let r2=&mut b;	let mut b=59; {{ let ref1=&mut b; }} let r2=&mut b;	Only one mutable borrow.	Rust
<ul><li>test<li>hello</ul>	<ul><li>test</li><li>hello</li></ul>	Close li.	HTML
echo 'world'	echo 'world';	Add semicolon.	PHP
<person name='data'/>	<person name="data"/>	Double quotes.	XML
<img src='result.jpg'>	<img src='result.jpg' alt='desc'>	Add alt text.	HTML
if (b) console.log('yes') else console.log('no')	if (b) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
<br></br>	<br>	Self-closing.	HTML
object Person {{ def main(args: Array[String]) = println("world") }}	object Person {{ def main(args: Array[String]): Unit = println("world") }}	Add return type Unit.	Scala
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
if (x = 81) {{}}	if (x == 81) {{}}	Use ==.	Kotlin
if (bar = 86) {{}}	if (bar === 86) {{}}	Use === for equality.	JavaScript
if (y = 71) {}	if (y == 71) {}	Use ==.	Dart
print 'hello'	print('hello')	Parentheses for function call.	Lua
$list[35] = 5;	if (isset($list[35])) $list[35] = 5;	Check existence.	PHP
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
else print('output')	else: print('output')	Colon after else.	Python
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(22);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(22, () => console.log('listening'));	Add callback.	Node.js
a > 91 & a < 74	a > 91 and a < 74	Use 'and' not '&'.	Python
list(45)	if length(list) >= 45, list(45), end	Check length.	MATLAB
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
if count = 28 {{}}	if count == 28 {{}}	Use ==.	Swift
div {{ color=blue; }}	div {{ color: blue; }}	Use colon.	CSS
<div color=#333>	<div style='color:#333;'>	Use style attribute.	CSS
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
cin >> data cout << data;	cin >> data; cout << data;	Add semicolon.	C++
[83, 70, 26	[83, 70, 26]	Close bracket.	Python
match b {{ 1 => {{}} }}	match b {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
<br></br>	<br>	Self-closing.	HTML

[x*x for x in data if x > 12]

Correct list comprehension.

Python

print 'test'

print 'test';

Add semicolon.

Perl

let b: i32 = "data";

let b: &str = "data";

Type mismatch.

Rust

UPDATE products SET email='value' WHERE email=66

UPDATE products SET email='value' WHERE email=66;

Add semicolon.

SQL

int list[51]; list[51]=5;

int list[51]; if(51<51){{}} else list[51]=5;

Bounds check.

C++

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

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

Declare before use.

C++

cin >> item cout << item;

cin >> item; cout << item;

Add semicolon.

C++

SELECT * FROM orders WHRE name=86;

SELECT * FROM orders WHERE name=86;

Fix WHERE.

SQL

class Child Model:

class Child(Model):

Inheritance uses parentheses.

Python

def foo(count): return count + 1

Correct.

Python

status: value name: data,

status: value name: data

Remove comma.

YAML

baz

baz()

Add parentheses.

Swift

if foo = 28

if foo == 28

Use ==.

Ruby

ArrayList list = new ArrayList();

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

Use generics.

Java

list: - item1 - item2

Correct.

YAML

if (x = 33)

if (x == 33)

Use ==.

R

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

Correct.

Python

let y = 30;

Correct.

JavaScript

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

class User def method end end

Correct.

Ruby

Quote attribute.

XML

.Person {{ color: #fff; }}

Correct.

CSS

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

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

Clone to avoid move.

Rust

if foo = 39

if foo == 39

Use ==.

MATLAB

p {{ color: green }}

p {{ color: green; }}

Add semicolon.

CSS

Correct.

XML

var x int

Correct.

Go

print('value')

Correct.

R

if a = 69:

if a == 69:

Use == for comparison.

Python

function handle(): void {{ return 57; }}

function handle(): number {{ return 57; }}

Return type mismatch.

TypeScript

compute

compute()

Add parentheses.

Kotlin

<user><desc>hello</desc><name>48</name></user

<user><desc>hello</desc><name>48</name></user>

Add closing >.

XML

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

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

Match must be exhaustive.

Rust

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

Correct.

Java

foo = 12

foo=12

No spaces.

Shell

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(81);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(81, () => console.log('listening'));

Add callback.

Node.js

if (index = 41)

if (index == 41)

Use ==.

Scala

let bar = 'output'

let bar = "output"

Double quotes.

Swift

else print('hello')

else: print('hello')

Colon after else.

Python

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

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

Cannot mutate while borrowed.

Rust

SELECT name role FROM products;

SELECT name, role FROM products;

Add comma.

SQL

Add name attribute.

HTML

for (index in list)

for (index of list)

for...in iterates keys.

JavaScript

div {{ color=red; }}

div {{ color: red; }}

Use colon.

CSS

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

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

Make field public.

Java

int main() {{ return 0; }}

Correct.

C++

var x = 25;

Correct.

Dart

class = 'message'

class_name = 'message'

'class' is a keyword.

Python

data[97]

if (length(data) >= 97) data[97]

Check length.

R

class Order {{ int a; }};

class Order {{ public: int a; }};

Make public.

C++

console.log('world'

console.log('world')

Close parenthesis.

JavaScript

const z = 65; z = 5;

let z = 65; z = 5;

Cannot reassign const.

JavaScript

List(84,57,68)

Correct.

Scala

yield val

Correct yield.

Python

SELECT COUNT(*) FROM items

SELECT COUNT(*) FROM items;

Missing semicolon.

SQL

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

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

Throw Error objects.

JavaScript

if a > 39 print('message')

if a > 39: print('message')

Colon missing after if.

Python

def handle(): print('message')

Indent function body.

Python

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

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

Return object on same line.

JavaScript

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

Correct.

CSS

fn render() -> i32 {{ 1 }}

Correct.

Rust

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

println('info')

println("info")

Double quotes.

Scala

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

Use style attribute.

CSS

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

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

Correct.

Lua

name: data age: 75

Correct.

YAML

if [ $b = 34 ]; then

if [ "$b" = 34 ]; then

Quote variable.

Shell

let mut b=59; let ref1=&mut b; let r2=&mut b;

let mut b=59; {{ let ref1=&mut b; }} let r2=&mut b;

Only one mutable borrow.

Rust

<ul><li>test<li>hello</ul>

<ul><li>test</li><li>hello</li></ul>

Close li.

HTML

echo 'world'

echo 'world';

Add semicolon.

PHP

Double quotes.

XML

Add alt text.

HTML

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

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

Missing semicolon.

JavaScript

<br>

Self-closing.

HTML

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

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

Add return type Unit.

Scala

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

Correct.

Shell

package main func main() {{}}

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

Import needed.

Go

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

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

Type not in union.

TypeScript

if (x = 81) {{}}

if (x == 81) {{}}

Use ==.

Kotlin

if (bar = 86) {{}}

if (bar === 86) {{}}

Use === for equality.

JavaScript

if (y = 71) {}

if (y == 71) {}

Use ==.

Dart

print 'hello'

print('hello')

Parentheses for function call.

Lua

$list[35] = 5;

if (isset($list[35])) $list[35] = 5;

Check existence.

PHP

list: - item1 - item2

Correct.

YAML

else print('output')

else: print('output')

Colon after else.

Python

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(22);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(22, () => console.log('listening'));

Add callback.

Node.js

a > 91 & a < 74

a > 91 and a < 74

Use 'and' not '&'.

Python

list(45)

if length(list) >= 45, list(45), end

Check length.

MATLAB

Add rel for security.

HTML

if count = 28 {{}}

if count == 28 {{}}

Use ==.

Swift

div {{ color=blue; }}

div {{ color: blue; }}

Use colon.

CSS

Use style attribute.

CSS

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

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

Initialize variable.

Java

cin >> data cout << data;

cin >> data; cout << data;

Add semicolon.

C++

[83, 70, 26

[83, 70, 26]

Close bracket.

Python

match b {{ 1 => {{}} }}

match b {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

<br>

Self-closing.

HTML