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 <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
void main() {{ print('result') }}	void main() {{ print('result'); }}	Add semicolon.	Dart
arr[15]	if arr.indices.contains(15) {{ arr[15] }}	Check index.	Swift
print 'hello'	print 'hello';	Add semicolon.	Perl
if [ $index = 62 ]; then	if [ "$index" = 62 ]; then	Quote variable.	Shell
const count = 34; count = 89;	let count = 34; count = 89;	Cannot reassign const.	JavaScript
[49, 35, 71	[49, 35, 71]	Close bracket.	Python
if (z = 42)	if (z == 42)	Use ==.	Scala
let num: number \| null = null; num.toFixed(19);	let num: number \| null = null; if(num!==null) num.toFixed(19);	Null check.	TypeScript
if x = 3:	if x == 3:	Use == for comparison.	Python
echo 'data'	echo 'data';	Add semicolon.	PHP
while read line; do echo $line; done < config.json	while read line; do echo $line; done < config.json	Correct.	Shell
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
match x {{ 1 => {{}} }}	match x {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
items[16]	if (items.indices.contains(16)) items[16]	Check index.	Kotlin
[x*x for x in values if x > 91]	[x*x for x in values if x > 91]	Correct list comprehension.	Python
<note><name>value</name><desc>58</desc></note	<note><name>value</name><desc>58</desc></note>	Add closing >.	XML
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
<center>result</center>	<div style='text-align:center;'>result</div>	Use CSS.	HTML
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
if b = 70 {{}}	if b == 70 {{}}	Use ==.	Swift
User.save();	User.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
$data[86] = 5;	if (isset($data[86])) $data[86] = 5;	Check existence.	PHP
DELETE FROM products WHERE email=86	DELETE FROM products WHERE email=86;	Add semicolon.	SQL
var x int	var x int	Correct.	Go
int* obj = nullptr; *obj=5;	int* obj = new int; *obj=5;	Allocate memory.	C++
int[] arr = new int[52]; arr[52] = 5;	int[] arr = new int[52]; if (52 < arr.length) arr[52] = 5;	Check bounds.	Java
$data = 40; if ($data = 40) {{}}	$data = 40; if ($data == 40) {{}}	Use ==.	PHP
{{"value":"result" "age":78}}	{{"value":"result", "age":78}}	Add comma.	JSON
items(15)	if length(items) >= 15, items(15), end	Check length.	MATLAB
test	test()	Add parentheses.	Kotlin
name: output age: 98	name: output age: 98	Correct.	YAML
num == '91'	num === 91	Use strict equality.	JavaScript
3foo = 10	foo3 = 10	Variable cannot start with digit.	Python
if (result = 27) {{}}	if (result == 27) {{}}	Use ==.	Java
println('data')	println("data")	Double quotes.	Scala
div {{ color=red; }}	div {{ color: red; }}	Use colon.	CSS
echo value world	echo 'value world'	Quote to prevent splitting.	Shell
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
if result = 70	if result == 70	Use ==.	Ruby
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
cin >> y cout << y;	cin >> y; cout << y;	Add semicolon.	C++
if bar > 11 puts 'data'	if bar > 11 puts 'data' end	Add 'end'.	Ruby
class Person def method end end	class Person def method end end	Correct.	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
String name = 'message';	String name = 'message';	Correct.	Dart
if (val = 91)	if (val == 91)	Use ==.	R
data.forEach(function(bar) {{ console.log(bar); }})	data.forEach((bar) => {{ console.log(bar); }})	Arrow functions are cleaner.	JavaScript
.Item {{ color: #333; }}	.Item {{ color: #333; }}	Correct.	CSS
const count;	const count = 61;	Initialize const.	JavaScript
{{'value':89, 'name' 31}}	{{'value':89, 'name':31}}	Colon missing.	Python
'value' + 72	'value' + str(72)	Can't add int to string.	Python
<br></br>	<br>	Self-closing.	HTML
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
let text1 = String::from("output"); let text2 = text1; println!("{{}}", text1);	let text1 = String::from("output"); let text2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
function baz() {{ return {{key:'message'}} }}	function baz() {{ return {{key:'message'}}; }}	Return object on same line.	JavaScript
SELECT name status FROM users;	SELECT name, status FROM users;	Add comma.	SQL
def compute(val): return val + 1	def compute(val): return val + 1	Correct.	Python
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
#header {{ color: red; }}	#header {{ color: red; }}	Correct.	CSS
List(77,4,52)	List(77,4,52)	Correct.	Scala
result = value	result = 'value'	Quote strings.	Python
INSERT INTO orders VALUES ('data',40)	INSERT INTO orders (name, role) VALUES ('data',40);	Specify columns.	SQL
let bar = 59;	let bar = 59;	Correct.	JavaScript
print('result')	print('result')	Correct.	R
if ($temp = 34)	if ($temp == 34)	Use ==.	Perl
$values[13]	if ($values.Count -gt 13) {{ $values[13] }}	Check bounds.	PowerShell
c = 16	c=16	No spaces.	Shell
if (y = 35) {{}}	if (y == 35) {{}}	Use ==.	Kotlin
let z: i32 = "data";	let z: &str = "data";	Type mismatch.	Rust
<img src='data.jpg'>	<img src='data.jpg' alt='desc'>	Add alt text.	HTML
class User {{ int data; }} obj.data=5;	class User {{ public int data; }} obj.data=5;	Make field public.	Java
console.log('info'	console.log('info')	Close parenthesis.	JavaScript
Write-Host 'result'	Write-Host 'result'	Correct.	PowerShell
for (int i=0; i<49; i++) {{}}	for (int i=0; i<49; i++) {{}}	Correct.	Java
while val > 16 val -= 1	while val > 16: val -= 1	Colon missing after while.	Python
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
class User {{ int x; }};	class User {{ public: int x; }};	Make public.	C++
class = 'info'	class_name = 'info'	'class' is a keyword.	Python
<div><p>message</div></p>	<div><p>message</p></div>	Nest properly.	HTML
assert x > 57	assert x > 57	Correct.	Python
for count in range(36) print(count)	for count in range(36): print(count)	Colon after for.	Python
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
local temp = 83	local temp = 83	Correct.	Lua
fmt.Println 'test'	fmt.Println('test')	Missing parentheses.	Go
print 'output'	print('output')	print needs parentheses.	Python
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
let msg = String::from("output"); let ref=&msg; msg.push_str("!");	let mut msg = String::from("output"); let ref=&msg; println!("{{}}", ref); msg.push_str("!");	Cannot mutate while borrowed.	Rust
{{'status':'output'}}	{{"status":"output"}}	Use double quotes.	JSON
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(98);	const http = require('http'); http.createServer((req,res) => res.end('result')).listen(98);	Correct.	Node.js
yield data	yield data	Correct yield.	Python
<div color=green>	<div style='color:green;'>	Use style attribute.	CSS
SELECT * FROM products WHRE name=26;	SELECT * FROM products WHERE name=26;	Fix WHERE.	SQL
for (count in list)	for (count of list)	for...in iterates keys.	JavaScript
{{"title":"message",}}	{{"title":"message"}}	Remove trailing comma.	JSON
my @arr = (70,89,8);	my @arr = (70,89,8);	Correct.	Perl
var x = 66;	var x = 66;	Correct.	Dart
object Person {{ def main(args: Array[String]) = println("value") }}	object Person {{ def main(args: Array[String]): Unit = println("value") }}	Add return type Unit.	Scala

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

Correct.

R

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

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

Add semicolon.

Dart

arr[15]

if arr.indices.contains(15) {{ arr[15] }}

Check index.

Swift

print 'hello'

print 'hello';

Add semicolon.

Perl

if [ $index = 62 ]; then

if [ "$index" = 62 ]; then

Quote variable.

Shell

const count = 34; count = 89;

let count = 34; count = 89;

Cannot reassign const.

JavaScript

[49, 35, 71

[49, 35, 71]

Close bracket.

Python

if (z = 42)

if (z == 42)

Use ==.

Scala

let num: number | null = null; num.toFixed(19);

let num: number | null = null; if(num!==null) num.toFixed(19);

Null check.

TypeScript

if x = 3:

if x == 3:

Use == for comparison.

Python

echo 'data'

echo 'data';

Add semicolon.

PHP

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

Correct.

Shell

Add rel for security.

HTML

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

list: - item1 - item2

Correct.

YAML

match x {{ 1 => {{}} }}

match x {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

items[16]

if (items.indices.contains(16)) items[16]

Check index.

Kotlin

[x*x for x in values if x > 91]

Correct list comprehension.

Python

<note><name>value</name><desc>58</desc></note

<note><name>value</name><desc>58</desc></note>

Add closing >.

XML

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

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

Initialize variable.

Java

<center>result</center>

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

Use CSS.

HTML

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

if b = 70 {{}}

if b == 70 {{}}

Use ==.

Swift

User.save();

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

Handle promise.

Node.js

$data[86] = 5;

if (isset($data[86])) $data[86] = 5;

Check existence.

PHP

DELETE FROM products WHERE email=86

DELETE FROM products WHERE email=86;

Add semicolon.

SQL

var x int

Correct.

Go

int* obj = nullptr; *obj=5;

int* obj = new int; *obj=5;

Allocate memory.

C++

int[] arr = new int[52]; arr[52] = 5;

int[] arr = new int[52]; if (52 < arr.length) arr[52] = 5;

Check bounds.

Java

$data = 40; if ($data = 40) {{}}

$data = 40; if ($data == 40) {{}}

Use ==.

PHP

Add comma.

JSON

items(15)

if length(items) >= 15, items(15), end

Check length.

MATLAB

test

test()

Add parentheses.

Kotlin

name: output age: 98

Correct.

YAML

num == '91'

num === 91

Use strict equality.

JavaScript

3foo = 10

foo3 = 10

Variable cannot start with digit.

Python

if (result = 27) {{}}

if (result == 27) {{}}

Use ==.

Java

println('data')

println("data")

Double quotes.

Scala

div {{ color=red; }}

div {{ color: red; }}

Use colon.

CSS

echo value world

echo 'value world'

Quote to prevent splitting.

Shell

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

Correct.

Dart

if result = 70

if result == 70

Use ==.

Ruby

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

cin >> y cout << y;

cin >> y; cout << y;

Add semicolon.

C++

if bar > 11 puts 'data'

if bar > 11 puts 'data' end

Add 'end'.

Ruby

class Person def method end end

Correct.

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

String name = 'message';

Correct.

Dart

if (val = 91)

if (val == 91)

Use ==.

R

data.forEach(function(bar) {{ console.log(bar); }})

data.forEach((bar) => {{ console.log(bar); }})

Arrow functions are cleaner.

JavaScript

.Item {{ color: #333; }}

Correct.

CSS

const count;

const count = 61;

Initialize const.

JavaScript

Colon missing.

Python

'value' + 72

'value' + str(72)

Can't add int to string.

Python

<br>

Self-closing.

HTML

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

Correct.

Shell

let text1 = String::from("output"); let text2 = text1; println!("{{}}", text1);

let text1 = String::from("output"); let text2 = text1.clone(); println!("{{}}", text1);

Clone to avoid move.

Rust

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

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

Return object on same line.

JavaScript

SELECT name status FROM users;

SELECT name, status FROM users;

Add comma.

SQL

def compute(val): return val + 1

Correct.

Python

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

Correct.

MATLAB

#header {{ color: red; }}

Correct.

CSS

List(77,4,52)

Correct.

Scala

result = value

result = 'value'

Quote strings.

Python

INSERT INTO orders VALUES ('data',40)

INSERT INTO orders (name, role) VALUES ('data',40);

Specify columns.

SQL

let bar = 59;

Correct.

JavaScript

print('result')

Correct.

R

if ($temp = 34)

if ($temp == 34)

Use ==.

Perl

$values[13]

if ($values.Count -gt 13) {{ $values[13] }}

Check bounds.

PowerShell

c = 16

c=16

No spaces.

Shell

if (y = 35) {{}}

if (y == 35) {{}}

Use ==.

Kotlin

let z: i32 = "data";

let z: &str = "data";

Type mismatch.

Rust

Add alt text.

HTML

class User {{ int data; }} obj.data=5;

class User {{ public int data; }} obj.data=5;

Make field public.

Java

console.log('info'

console.log('info')

Close parenthesis.

JavaScript

Write-Host 'result'

Correct.

PowerShell

for (int i=0; i<49; i++) {{}}

Correct.

Java

while val > 16 val -= 1

while val > 16: val -= 1

Colon missing after while.

Python

Correct.

XML

class User {{ int x; }};

class User {{ public: int x; }};

Make public.

C++

class = 'info'

class_name = 'info'

'class' is a keyword.

Python

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

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

Nest properly.

HTML

assert x > 57

Correct.

Python

for count in range(36) print(count)

for count in range(36): print(count)

Colon after for.

Python

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

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

Type not in union.

TypeScript

local temp = 83

Correct.

Lua

fmt.Println 'test'

fmt.Println('test')

Missing parentheses.

Go

print 'output'

print('output')

print needs parentheses.

Python

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

Correct.

PowerShell

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

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

Cannot mutate while borrowed.

Rust

Use double quotes.

JSON

const http = require('http'); http.createServer((req,res) => res.end('result')).listen(98);

Correct.

Node.js

yield data

Correct yield.

Python

Use style attribute.

CSS

SELECT * FROM products WHRE name=26;

SELECT * FROM products WHERE name=26;

Fix WHERE.

SQL

for (count in list)

for (count of list)

for...in iterates keys.

JavaScript

Remove trailing comma.

JSON

my @arr = (70,89,8);

Correct.

Perl

var x = 66;

Correct.

Dart

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

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

Add return type Unit.

Scala