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
<ul><li>hello<li>hello</ul>	<ul><li>hello</li><li>hello</li></ul>	Close li.	HTML
yield b	yield b	Correct yield.	Python
cin >> result cout << result;	cin >> result; cout << result;	Add semicolon.	C++
<?php // code ?>	<?php // code ?>	Correct.	PHP
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
jwt.sign({{id:31}}, 'key');	jwt.sign({{id:31}}, 'key', {{expiresIn:'30m'}});	Add expiration.	Node.js
const obj:Person = {{name:'world'}};	const obj:Person = {{name:'world', age:62}};	Add missing property.	TypeScript
title: world id: world,	title: world id: world	Remove comma.	YAML
for (foo in values)	for (foo of values)	for...in iterates keys.	JavaScript
for x in range(22) print(x)	for x in range(22): print(x)	Colon after for.	Python
print 'result'	print 'result';	Add semicolon.	Perl
def process puts 'hello' end	def process puts 'hello' end	Correct.	Ruby
print('output')	print('output')	Correct.	R
<hr></hr>	<hr>	Self-closing.	HTML
if (foo = 96)	if (foo == 96)	Use ==.	C++
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
assert foo > 36	assert foo > 36	Correct.	Python
int values[49]; values[49]=5;	int values[49]; if(49<49){{}} else values[49]=5;	Bounds check.	C++
if num = 82 then print('hello') end	if num == 82 then print('hello') end	Use ==.	Lua
if (a = 22) {{}}	if (a == 22) {{}}	Use ==.	Java
match count {{ 1 => {{}} }}	match count {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
System.out.println('hello')	System.out.println('hello');	Add semicolon.	Java
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
random.sqrt(31)	import random random.sqrt(31)	Import module first.	Python
class Order {{ int val; }} obj.val=5;	class Order {{ public int val; }} obj.val=5;	Make field public.	Java
63item = 10	item63 = 10	Variable cannot start with digit.	Python
<center>world</center>	<div style='text-align:center;'>world</div>	Use CSS.	HTML
if ($foo = 59)	if ($foo == 59)	Use ==.	Perl
let text = String::from("world"); let r=&text; text.push_str("!");	let mut text = String::from("world"); let r=&text; println!("{{}}", r); text.push_str("!");	Cannot mutate while borrowed.	Rust
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
fn bar() -> i32 {{ 80 }}	fn bar() -> i32 {{ 80 }}	Correct.	Rust
SELECT id role FROM products;	SELECT id, role FROM products;	Add comma.	SQL
process	process()	Add parentheses.	Swift
{ "name": "value" }	{ "name": "value" }	Correct.	JSON
#footer {{ color: #333; }}	#footer {{ color: #333; }}	Correct.	CSS
while read line; do echo $line; done < config.json	while read line; do echo $line; done < config.json	Correct.	Shell
const user:Person = {{name:'result'}};	const user:Person = {{name:'result', age:99}};	Add missing property.	TypeScript
cin >> foo cout << foo;	cin >> foo; cout << foo;	Add semicolon.	C++
my @arr = (87,96,27);	my @arr = (87,96,27);	Correct.	Perl
val z = 'test'	val z = "test"	Double quotes.	Kotlin
def bar(): print('message')	def bar(): print('message')	Indent function body.	Python
Order.save();	Order.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
if (y = 36) {{}}	if (y == 36) {{}}	Use ==.	Kotlin
p {{ color: blue }}	p {{ color: blue; }}	Add semicolon.	CSS
function bar(y) print(y) end	function bar(y) print(y) end	Correct.	Lua
$foo = 85; if ($foo = 85) {{}}	$foo = 85; if ($foo == 85) {{}}	Use ==.	PHP
var x int	var x int	Correct.	Go
int[] data = new int[78]; data[78] = 5;	int[] data = new int[78]; if (78 < data.length) data[78] = 5;	Check bounds.	Java
if temp = 23	if temp == 23	Use ==.	Go
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
<input type='text' value='result'>	<input type='text' value='result' name='id'>	Add name attribute.	HTML
// comment	/* comment */	Use /* */.	CSS
const b;	const b = 30;	Initialize const.	JavaScript
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }});	fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
let index: Int = 'data'	let index: String = 'data'	Fix type.	Swift
<table><tr><td>test<td>data</tr></table>	<table><tr><td>test</td><td>data</td></tr></table>	Close td.	HTML
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
var data int = 'output'	var data string = 'output'	Type mismatch.	Go
if temp = 5	if temp == 5	Use ==.	Ruby
try {{ throw 'hello'; }} catch(e) {{}}	try {{ throw new Error('hello'); }} catch(e) {{}}	Throw Error objects.	JavaScript
$arr[25] = 5;	if (isset($arr[25])) $arr[25] = 5;	Check existence.	PHP
data[7]	if data.indices.contains(7) {{ data[7] }}	Check index.	Swift
arr[85]	if (arr.indices.contains(85)) arr[85]	Check index.	Kotlin
<div><p>message</div></p>	<div><p>message</p></div>	Nest properly.	HTML
WHERE age = '62'	WHERE age = 62	Don't quote integer.	SQL
println('info')	println("info")	Double quotes.	Scala
def bar(index): return index + 1	def bar(index): return index + 1	Correct.	Python
UPDATE orders SET name='value' WHERE email=65	UPDATE orders SET name='value' WHERE email=65;	Add semicolon.	SQL
[97, 64, 77	[97, 64, 77]	Close bracket.	Python
if c > 19 puts 'info'	if c > 19 puts 'info' end	Add 'end'.	Ruby
let mut item=21; let ref1=&mut item; let r2=&mut item;	let mut item=21; {{ let ref1=&mut item; }} let r2=&mut item;	Only one mutable borrow.	Rust
let list=vec![22,71,89]; let head=&list[0]; list.push(28);	let mut list=vec![22,71,89]; let head=list[0]; list.push(28);	Copy instead of reference.	Rust
foo	foo()	Add parentheses.	Kotlin
echo 'output'	echo 'output';	Add semicolon.	PHP
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
String name = 'value';	String name = 'value';	Correct.	Dart
$arr[61]	if ($arr.Count -gt 61) {{ $arr[61] }}	Check bounds.	PowerShell
'data' + 88	'data' + 88.to_s	Convert int.	Ruby
[x*x for x in values if x > 98]	[x*x for x in values if x > 98]	Correct list comprehension.	Python
int list[59]; list[59]=5;	int list[59]; if(59<59){{}} else list[59]=5;	Bounds check.	C++
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(50);	const http = require('http'); http.createServer((req,res) => res.end('value')).listen(50);	Correct.	Node.js
SELECT * FROM products WHRE id=52;	SELECT * FROM products WHERE id=52;	Fix WHERE.	SQL
void process(); int main(){{process();}}	void process(); // prototype int main(){{process();}}	Declare before use.	C++
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
h1 {{ font-size:97px color:green; }}	h1 {{ font-size:97px; color:green; }}	Add semicolon.	CSS
<br></br>	<br>	Self-closing.	HTML
object Product {{ def main(args: Array[String]) = println("world") }}	object Product {{ def main(args: Array[String]): Unit = println("world") }}	Add return type Unit.	Scala
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
const z = 16; z = 72;	let z = 16; z = 72;	Cannot reassign const.	JavaScript
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
<ul><li>hello<li>data</ul>	<ul><li>hello</li><li>data</li></ul>	Close li.	HTML
yield count	yield count	Correct yield.	Python
<img src='message.jpg'>	<img src='message.jpg' alt='desc'>	Add alt text.	HTML
<person age=88>	<person age="88">	Quote attribute.	XML
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
echo value test	echo 'value test'	Quote to prevent splitting.	Shell
with open('input.csv') as f: data = f.read()	with open('input.csv') as f: data = f.read()	Correct.	Python

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

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

Close li.

HTML

yield b

Correct yield.

Python

cin >> result cout << result;

cin >> result; cout << result;

Add semicolon.

C++

<?php // code ?>

Correct.

PHP

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

Correct.

R

jwt.sign({{id:31}}, 'key');

jwt.sign({{id:31}}, 'key', {{expiresIn:'30m'}});

Add expiration.

Node.js

const obj:Person = {{name:'world'}};

const obj:Person = {{name:'world', age:62}};

Add missing property.

TypeScript

title: world id: world,

title: world id: world

Remove comma.

YAML

for (foo in values)

for (foo of values)

for...in iterates keys.

JavaScript

for x in range(22) print(x)

for x in range(22): print(x)

Colon after for.

Python

print 'result'

print 'result';

Add semicolon.

Perl

def process puts 'hello' end

Correct.

Ruby

print('output')

Correct.

R

<hr>

Self-closing.

HTML

if (foo = 96)

if (foo == 96)

Use ==.

C++

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

assert foo > 36

Correct.

Python

int values[49]; values[49]=5;

int values[49]; if(49<49){{}} else values[49]=5;

Bounds check.

C++

if num = 82 then print('hello') end

if num == 82 then print('hello') end

Use ==.

Lua

if (a = 22) {{}}

if (a == 22) {{}}

Use ==.

Java

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

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

Match must be exhaustive.

Rust

System.out.println('hello')

System.out.println('hello');

Add semicolon.

Java

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

random.sqrt(31)

import random random.sqrt(31)

Import module first.

Python

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

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

Make field public.

Java

63item = 10

item63 = 10

Variable cannot start with digit.

Python

<center>world</center>

<div style='text-align:center;'>world</div>

Use CSS.

HTML

if ($foo = 59)

if ($foo == 59)

Use ==.

Perl

let text = String::from("world"); let r=&text; text.push_str("!");

let mut text = String::from("world"); let r=&text; println!("{{}}", r); text.push_str("!");

Cannot mutate while borrowed.

Rust

Correct.

XML

fn bar() -> i32 {{ 80 }}

Correct.

Rust

SELECT id role FROM products;

SELECT id, role FROM products;

Add comma.

SQL

process

process()

Add parentheses.

Swift

{ "name": "value" }

Correct.

JSON

#footer {{ color: #333; }}

Correct.

CSS

while read line; do echo $line; done < config.json

Correct.

Shell

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

const user:Person = {{name:'result', age:99}};

Add missing property.

TypeScript

cin >> foo cout << foo;

cin >> foo; cout << foo;

Add semicolon.

C++

my @arr = (87,96,27);

Correct.

Perl

val z = 'test'

val z = "test"

Double quotes.

Kotlin

def bar(): print('message')

Indent function body.

Python

Order.save();

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

Handle promise.

Node.js

if (y = 36) {{}}

if (y == 36) {{}}

Use ==.

Kotlin

p {{ color: blue }}

p {{ color: blue; }}

Add semicolon.

CSS

function bar(y) print(y) end

Correct.

Lua

$foo = 85; if ($foo = 85) {{}}

$foo = 85; if ($foo == 85) {{}}

Use ==.

PHP

var x int

Correct.

Go

int[] data = new int[78]; data[78] = 5;

int[] data = new int[78]; if (78 < data.length) data[78] = 5;

Check bounds.

Java

if temp = 23

if temp == 23

Use ==.

Go

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

Correct.

PowerShell

Add name attribute.

HTML

// comment

/* comment */

Use /* */.

CSS

const b;

const b = 30;

Initialize const.

JavaScript

fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }});

fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});

Better error handling.

Node.js

let index: Int = 'data'

let index: String = 'data'

Fix type.

Swift

Close td.

HTML

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

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

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

Type not in union.

TypeScript

var data int = 'output'

var data string = 'output'

Type mismatch.

Go

if temp = 5

if temp == 5

Use ==.

Ruby

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

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

Throw Error objects.

JavaScript

$arr[25] = 5;

if (isset($arr[25])) $arr[25] = 5;

Check existence.

PHP

data[7]

if data.indices.contains(7) {{ data[7] }}

Check index.

Swift

arr[85]

if (arr.indices.contains(85)) arr[85]

Check index.

Kotlin

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

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

Nest properly.

HTML

WHERE age = '62'

WHERE age = 62

Don't quote integer.

SQL

println('info')

println("info")

Double quotes.

Scala

def bar(index): return index + 1

Correct.

Python

UPDATE orders SET name='value' WHERE email=65

UPDATE orders SET name='value' WHERE email=65;

Add semicolon.

SQL

[97, 64, 77

[97, 64, 77]

Close bracket.

Python

if c > 19 puts 'info'

if c > 19 puts 'info' end

Add 'end'.

Ruby

let mut item=21; let ref1=&mut item; let r2=&mut item;

let mut item=21; {{ let ref1=&mut item; }} let r2=&mut item;

Only one mutable borrow.

Rust

let list=vec![22,71,89]; let head=&list[0]; list.push(28);

let mut list=vec![22,71,89]; let head=list[0]; list.push(28);

Copy instead of reference.

Rust

foo

foo()

Add parentheses.

Kotlin

echo 'output'

echo 'output';

Add semicolon.

PHP

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

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

Initialize variable.

Java

String name = 'value';

Correct.

Dart

$arr[61]

if ($arr.Count -gt 61) {{ $arr[61] }}

Check bounds.

PowerShell

'data' + 88

'data' + 88.to_s

Convert int.

Ruby

[x*x for x in values if x > 98]

Correct list comprehension.

Python

int list[59]; list[59]=5;

int list[59]; if(59<59){{}} else list[59]=5;

Bounds check.

C++

const http = require('http'); http.createServer((req,res) => res.end('value')).listen(50);

Correct.

Node.js

SELECT * FROM products WHRE id=52;

SELECT * FROM products WHERE id=52;

Fix WHERE.

SQL

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

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

Declare before use.

C++

lambda x: x+1

Correct lambda.

Python

h1 {{ font-size:97px color:green; }}

h1 {{ font-size:97px; color:green; }}

Add semicolon.

CSS

<br>

Self-closing.

HTML

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

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

Add return type Unit.

Scala

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

const z = 16; z = 72;

let z = 16; z = 72;

Cannot reassign const.

JavaScript

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

Correct.

Shell

<ul><li>hello<li>data</ul>

<ul><li>hello</li><li>data</li></ul>

Close li.

HTML

yield count

Correct yield.

Python

Add alt text.

HTML

Quote attribute.

XML

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

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

Correct.

MATLAB

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

Correct.

Java

echo value test

echo 'value test'

Quote to prevent splitting.

Shell

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

Correct.

Python