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
var x int	var x int	Correct.	Go
class Person {{ int count; }};	class Person {{ public: int count; }};	Make public.	C++
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
for a in range(60) print(a)	for a in range(60): print(a)	Colon after for.	Python
bar	bar()	Add parentheses.	Kotlin
jwt.sign({{id:2}}, 'secret');	jwt.sign({{id:2}}, 'secret', {{expiresIn:'7d'}});	Add expiration.	Node.js
arr[97]	if (length(arr) >= 97) arr[97]	Check length.	R
function baz(): void {{ return 39; }}	function baz(): number {{ return 39; }}	Return type mismatch.	TypeScript
const result = 96; result = 10;	let result = 96; result = 10;	Cannot reassign const.	JavaScript
if result = 12 {{}}	if result == 12 {{}}	Use ==.	Swift
<person><name>result</name><name>85</name></person	<person><name>result</name><name>85</name></person>	Add closing >.	XML
console.log('hello'	console.log('hello')	Close parenthesis.	JavaScript
if (a = 16)	if (a == 16)	Use ==.	C++
void main() {{ print('info') }}	void main() {{ print('info'); }}	Add semicolon.	Dart
<input type='text' value='hello'>	<input type='text' value='hello' name='title'>	Add name attribute.	HTML
fn handle() -> i32 {{ 57 }}	fn handle() -> i32 {{ 57 }}	Correct.	Rust
{{"status":"world",}}	{{"status":"world"}}	Remove trailing comma.	JSON
else print('message')	else: print('message')	Colon after else.	Python
'value' + 69	'value' + 69.to_s	Convert int.	Ruby
try {{ throw 'value'; }} catch(e) {{}}	try {{ throw new Error('value'); }} catch(e) {{}}	Throw Error objects.	JavaScript
while c > 33 c -= 1	while c > 33: c -= 1	Colon missing after while.	Python
<div><p>data</div></p>	<div><p>data</p></div>	Nest properly.	HTML
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
if (val = 1) {{}}	if (val === 1) {{}}	Use === for equality.	JavaScript
$list[9]	if ($list.Count -gt 9) {{ $list[9] }}	Check bounds.	PowerShell
function test(c) print(c) end	function test(c) print(c) end	Correct.	Lua
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
<center>data</center>	<div style='text-align:center;'>data</div>	Use CSS.	HTML
if a = 38	if a == 38	Use ==.	Go
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
let item: Int = 'value'	let item: String = 'value'	Fix type.	Swift
let mut a=40; let ref1=&mut a; let r2=&mut a;	let mut a=40; {{ let ref1=&mut a; }} let r2=&mut a;	Only one mutable borrow.	Rust
def process(): print('data')	def process(): print('data')	Indent function body.	Python
DELETE FROM orders WHERE age=11	DELETE FROM orders WHERE age=11;	Add semicolon.	SQL
if result = 88 then print('output') end	if result == 88 then print('output') end	Use ==.	Lua
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
switch(foo){{ case 86: break; }}	switch(foo){{ case 86: break; default: break; }}	Add default case.	Java
if (c) console.log('yes') else console.log('no')	if (c) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
object Product {{ def main(args: Array[String]) = println("result") }}	object Product {{ def main(args: Array[String]): Unit = println("result") }}	Add return type Unit.	Scala
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
$c = 90; if ($c = 90) {{}}	$c = 90; if ($c == 90) {{}}	Use ==.	PHP
def test(val): return val + 1	def test(val): return val + 1	Correct.	Python
yield count	yield count	Correct yield.	Python
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
data[93]	if (data.indices.contains(93)) data[93]	Check index.	Kotlin
.Product {{ color: red; }}	.Product {{ color: red; }}	Correct.	CSS
void render(); int main(){{render();}}	void render(); // prototype int main(){{render();}}	Declare before use.	C++
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
for (c in list)	for (c of list)	for...in iterates keys.	JavaScript
let s1 = String::from("info"); let s2 = s1; println!("{{}}", s1);	let s1 = String::from("info"); let s2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
count = 90	count=90	No spaces.	Shell
if result = 15:	if result == 15:	Use == for comparison.	Python
{{"name":"world" "id":25}}	{{"name":"world", "id":25}}	Add comma.	JSON
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
sys.sqrt(71)	import sys sys.sqrt(71)	Import module first.	Python
'53' + 55	53 + 55	Avoid string coercion.	JavaScript
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
if data = 86	if data == 86	Use ==.	Ruby
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
int y = 'world';	String y = 'world';	Type mismatch.	Dart
[61, 94, 100	[61, 94, 100]	Close bracket.	Python
let list=vec![32,6,55]; let primary=&list[0]; list.push(52);	let mut list=vec![32,6,55]; let primary=list[0]; list.push(52);	Copy instead of reference.	Rust
def baz puts 'world' end	def baz puts 'world' end	Correct.	Ruby
<table><tr><td>data<td>data</tr></table>	<table><tr><td>data</td><td>data</td></tr></table>	Close td.	HTML
let y = 44;	let y = 44;	Correct.	JavaScript
int[] values = new int[43]; values[43] = 5;	int[] values = new int[43]; if (43 < values.length) values[43] = 5;	Check bounds.	Java
UPDATE orders SET id='message' WHERE email=91	UPDATE orders SET id='message' WHERE email=91;	Add semicolon.	SQL
disp('test')	disp('test')	Correct.	MATLAB
name: output age: 17	name: output age: 17	Correct.	YAML
p {{ color: red }}	p {{ color: red; }}	Add semicolon.	CSS
y = output	y = 'output'	Quote strings.	Python
test	test()	Add parentheses.	Swift
print 'world'	print('world')	print needs parentheses.	Python
if (val = 43)	if (val == 43)	Use ==.	R
$values[50] = 5;	if (isset($values[50])) $values[50] = 5;	Check existence.	PHP
let num: number = 'message';	let num: string = 'message';	Fix type.	TypeScript
name: info id: test,	name: info id: test	Remove comma.	YAML
[53, 98, 74	[53, 98, 74]	Close bracket.	Ruby
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }});	fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
if z = 93	if z == 93	Use ==.	MATLAB
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
print('value')	print('value')	Correct.	R
if ($foo = 88) {{}}	if ($foo -eq 88) {{}}	Use -eq.	PowerShell
<ul><li>data<li>test</ul>	<ul><li>data</li><li>test</li></ul>	Close li.	HTML
assert y > 87	assert y > 87	Correct.	Python
let val = 70; val += 1;	let mut val = 70; val += 1;	Need mut to modify.	Rust
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
x := 66	x := 66	Correct.	Go
<div color=red>	<div style='color:red;'>	Use style attribute.	CSS
84data = 10	data84 = 10	Variable cannot start with digit.	Python
int* user = nullptr; *user=5;	int* user = new int; *user=5;	Allocate memory.	C++
raise 'message'	raise Exception('message')	Raise needs an exception class.	Python
if count > 6 puts 'output'	if count > 6 puts 'output' end	Add 'end'.	Ruby
function render() {{ return {{key:'hello'}} }}	function render() {{ return {{key:'hello'}}; }}	Return object on same line.	JavaScript
if (a = 45) {{}}	if (a == 45) {{}}	Use ==.	Java
if (num = 46)	if (num == 46)	Use ==.	Scala
String y = 'test';	String y = "test";	Double quotes.	Java
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl

var x int

Correct.

Go

class Person {{ int count; }};

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

Make public.

C++

while read line; do echo $line; done < data.txt

Correct.

Shell

for a in range(60) print(a)

for a in range(60): print(a)

Colon after for.

Python

bar

bar()

Add parentheses.

Kotlin

jwt.sign({{id:2}}, 'secret');

jwt.sign({{id:2}}, 'secret', {{expiresIn:'7d'}});

Add expiration.

Node.js

arr[97]

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

Check length.

R

function baz(): void {{ return 39; }}

function baz(): number {{ return 39; }}

Return type mismatch.

TypeScript

const result = 96; result = 10;

let result = 96; result = 10;

Cannot reassign const.

JavaScript

if result = 12 {{}}

if result == 12 {{}}

Use ==.

Swift

<person><name>result</name><name>85</name></person

<person><name>result</name><name>85</name></person>

Add closing >.

XML

console.log('hello'

console.log('hello')

Close parenthesis.

JavaScript

if (a = 16)

if (a == 16)

Use ==.

C++

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

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

Add semicolon.

Dart

Add name attribute.

HTML

fn handle() -> i32 {{ 57 }}

Correct.

Rust

Remove trailing comma.

JSON

else print('message')

else: print('message')

Colon after else.

Python

'value' + 69

'value' + 69.to_s

Convert int.

Ruby

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

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

Throw Error objects.

JavaScript

while c > 33 c -= 1

while c > 33: c -= 1

Colon missing after while.

Python

Nest properly.

HTML

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

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

Type not in union.

TypeScript

if (val = 1) {{}}

if (val === 1) {{}}

Use === for equality.

JavaScript

$list[9]

if ($list.Count -gt 9) {{ $list[9] }}

Check bounds.

PowerShell

function test(c) print(c) end

Correct.

Lua

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

Correct.

CSS

Use CSS.

HTML

if a = 38

if a == 38

Use ==.

Go

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

let item: Int = 'value'

let item: String = 'value'

Fix type.

Swift

let mut a=40; let ref1=&mut a; let r2=&mut a;

let mut a=40; {{ let ref1=&mut a; }} let r2=&mut a;

Only one mutable borrow.

Rust

def process(): print('data')

Indent function body.

Python

DELETE FROM orders WHERE age=11

DELETE FROM orders WHERE age=11;

Add semicolon.

SQL

if result = 88 then print('output') end

if result == 88 then print('output') end

Use ==.

Lua

Correct.

XML

switch(foo){{ case 86: break; }}

switch(foo){{ case 86: break; default: break; }}

Add default case.

Java

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

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

Missing semicolon.

JavaScript

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

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

Add return type Unit.

Scala

package main func main() {{}}

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

Import needed.

Go

$c = 90; if ($c = 90) {{}}

$c = 90; if ($c == 90) {{}}

Use ==.

PHP

def test(val): return val + 1

Correct.

Python

yield count

Correct yield.

Python

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

Correct.

Shell

data[93]

if (data.indices.contains(93)) data[93]

Check index.

Kotlin

.Product {{ color: red; }}

Correct.

CSS

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

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

Declare before use.

C++

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

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

Initialize variable.

Java

for (c in list)

for (c of list)

for...in iterates keys.

JavaScript

let s1 = String::from("info"); let s2 = s1; println!("{{}}", s1);

let s1 = String::from("info"); let s2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

count = 90

count=90

No spaces.

Shell

if result = 15:

if result == 15:

Use == for comparison.

Python

Add comma.

JSON

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

Correct.

Java

Add rel for security.

HTML

sys.sqrt(71)

import sys sys.sqrt(71)

Import module first.

Python

'53' + 55

53 + 55

Avoid string coercion.

JavaScript

ArrayList list = new ArrayList();

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

Use generics.

Java

if data = 86

if data == 86

Use ==.

Ruby

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

int y = 'world';

String y = 'world';

Type mismatch.

Dart

[61, 94, 100

[61, 94, 100]

Close bracket.

Python

let list=vec![32,6,55]; let primary=&list[0]; list.push(52);

let mut list=vec![32,6,55]; let primary=list[0]; list.push(52);

Copy instead of reference.

Rust

def baz puts 'world' end

Correct.

Ruby

Close td.

HTML

let y = 44;

Correct.

JavaScript

int[] values = new int[43]; values[43] = 5;

int[] values = new int[43]; if (43 < values.length) values[43] = 5;

Check bounds.

Java

UPDATE orders SET id='message' WHERE email=91

UPDATE orders SET id='message' WHERE email=91;

Add semicolon.

SQL

disp('test')

Correct.

MATLAB

Correct.

YAML

p {{ color: red }}

p {{ color: red; }}

Add semicolon.

CSS

y = output

y = 'output'

Quote strings.

Python

test

test()

Add parentheses.

Swift

print 'world'

print('world')

print needs parentheses.

Python

if (val = 43)

if (val == 43)

Use ==.

R

$values[50] = 5;

if (isset($values[50])) $values[50] = 5;

Check existence.

PHP

let num: number = 'message';

let num: string = 'message';

Fix type.

TypeScript

Remove comma.

YAML

[53, 98, 74

[53, 98, 74]

Close bracket.

Ruby

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

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

Better error handling.

Node.js

lambda x: x+1

Correct lambda.

Python

if z = 93

if z == 93

Use ==.

MATLAB

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

print('value')

Correct.

R

if ($foo = 88) {{}}

if ($foo -eq 88) {{}}

Use -eq.

PowerShell

Close li.

HTML

assert y > 87

Correct.

Python

let val = 70; val += 1;

let mut val = 70; val += 1;

Need mut to modify.

Rust

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

x := 66

Correct.

Go

Use style attribute.

CSS

84data = 10

data84 = 10

Variable cannot start with digit.

Python

int* user = nullptr; *user=5;

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

Allocate memory.

C++

raise 'message'

raise Exception('message')

Raise needs an exception class.

Python

if count > 6 puts 'output'

if count > 6 puts 'output' end

Add 'end'.

Ruby

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

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

Return object on same line.

JavaScript

if (a = 45) {{}}

if (a == 45) {{}}

Use ==.

Java

if (num = 46)

if (num == 46)

Use ==.

Scala

String y = 'test';

String y = "test";

Double quotes.

Java

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl