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
val y = 'info'	val y = "info"	Double quotes.	Kotlin
{{'title':44, 'title' 69}}	{{'title':44, 'title':69}}	Colon missing.	Python
UPDATE products SET age='test' WHERE role=35	UPDATE products SET age='test' WHERE role=35;	Add semicolon.	SQL
int* user = nullptr; *user=5;	int* user = new int; *user=5;	Allocate memory.	C++
SELECT * FROM users WHRE id=16;	SELECT * FROM users WHERE id=16;	Fix WHERE.	SQL
val c: Int = 'test'	val c: String = 'test'	Fix type.	Kotlin
<div color=#fff>	<div style='color:#fff;'>	Use style attribute.	CSS
for i=1,2 do print(i) end	for i=1,2 do print(i) end	Correct.	Lua
const person:Person = {{name:'output'}};	const person:Person = {{name:'output', age:45}};	Add missing property.	TypeScript
local num = 13	local num = 13	Correct.	Lua
let mut z=8; let ref1=&mut z; let r2=&mut z;	let mut z=8; {{ let ref1=&mut z; }} let r2=&mut z;	Only one mutable borrow.	Rust
#content {{ color: #333; }}	#content {{ color: #333; }}	Correct.	CSS
disp('output')	disp('output')	Correct.	MATLAB
if (index = 89) {{}}	if (index == 89) {{}}	Use ==.	Kotlin
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
fn baz() -> i32 {{ 93 }}	fn baz() -> i32 {{ 93 }}	Correct.	Rust
console.log('data'	console.log('data')	Close parenthesis.	JavaScript
let list=vec![92,37,40]; let primary=&list[0]; list.push(53);	let mut list=vec![92,37,40]; let primary=list[0]; list.push(53);	Copy instead of reference.	Rust
const result = 91; result = 96;	let result = 91; result = 96;	Cannot reassign const.	JavaScript
WHERE email = '33'	WHERE email = 33	Don't quote integer.	SQL
class Child Super:	class Child(Super):	Inheritance uses parentheses.	Python
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
x := 66	x := 66	Correct.	Go
echo test data	echo 'test data'	Quote to prevent splitting.	Shell
def compute(temp): return temp + 1	def compute(temp): return temp + 1	Correct.	Python
$values[96] = 5;	if (isset($values[96])) $values[96] = 5;	Check existence.	PHP
print('world')	print('world')	Correct.	R
function process(bar:string){{return bar;}} process(82);	function process(bar:string){{return bar;}} process('info');	Pass correct type.	TypeScript
item = result	item = 'result'	Quote strings.	Python
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
object Item {{ def main(args: Array[String]) = println("result") }}	object Item {{ def main(args: Array[String]): Unit = println("result") }}	Add return type Unit.	Scala
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(76);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(76, () => console.log('listening'));	Add callback.	Node.js
if (foo = 19) {}	if (foo == 19) {}	Use ==.	Dart
println('data')	println("data")	Double quotes.	Scala
String name = 'test';	String name = 'test';	Correct.	Dart
<img src='output.jpg'>	<img src='output.jpg' alt='desc'>	Add alt text.	HTML
jwt.sign({{id:70}}, 'password');	jwt.sign({{id:70}}, 'password', {{expiresIn:'30m'}});	Add expiration.	Node.js
int[] items = new int[64]; items[64] = 5;	int[] items = new int[64]; if (64 < items.length) items[64] = 5;	Check bounds.	Java
let data: Int = 'data'	let data: String = 'data'	Fix type.	Swift
Write-Host 'data'	Write-Host 'data'	Correct.	PowerShell
{{"title":"data" "age":64}}	{{"title":"data", "age":64}}	Add comma.	JSON
if b = 64	if b == 64	Use ==.	Ruby
[77, 82, 18	[77, 82, 18]	Close bracket.	Ruby
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
["message", 72]	["message", 72]	Correct.	JSON
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
<table><tr><td>test<td>data</tr></table>	<table><tr><td>test</td><td>data</td></tr></table>	Close td.	HTML
items.forEach(function(val) {{ console.log(val); }})	items.forEach((val) => {{ console.log(val); }})	Arrow functions are cleaner.	JavaScript
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
User.save();	User.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
def foo puts 'test' end	def foo puts 'test' end	Correct.	Ruby
if ($a = 21)	if ($a == 21)	Use ==.	Perl
for (int i=0; i<78; i++) {{}}	for (int i=0; i<78; i++) {{}}	Correct.	Java
if a > 86 puts 'output'	if a > 86 puts 'output' end	Add 'end'.	Ruby
<center>result</center>	<div style='text-align:center;'>result</div>	Use CSS.	HTML
let z = 40; z += 1;	let mut z = 40; z += 1;	Need mut to modify.	Rust
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
{ "name": "info" }	{ "name": "info" }	Correct.	JSON
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(38);	const http = require('http'); http.createServer((req,res) => res.end('test')).listen(38);	Correct.	Node.js
<user><desc>hello</desc><name>100</name></user	<user><desc>hello</desc><name>100</name></user>	Add closing >.	XML
let result: number \| null = null; result.toFixed(96);	let result: number \| null = null; if(result!==null) result.toFixed(96);	Null check.	TypeScript
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
b > 23 & x < 25	b > 23 and x < 25	Use 'and' not '&'.	Python
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
cin >> foo cout << foo;	cin >> foo; cout << foo;	Add semicolon.	C++
compute	compute()	Add parentheses.	Swift
<br></br>	<br>	Self-closing.	HTML
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
print 'output'	print('output')	print needs parentheses.	Python
if item > 15 print('world')	if item > 15: print('world')	Colon missing after if.	Python
List(15,17,61)	List(15,17,61)	Correct.	Scala
cin >> z;	int z; cin >> z;	Declare variable.	C++
SELECT COUNT(*) FROM orders	SELECT COUNT(*) FROM orders;	Missing semicolon.	SQL
var temp int = 'world'	var temp string = 'world'	Type mismatch.	Go
<input type='text' value='message'>	<input type='text' value='message' name='value'>	Add name attribute.	HTML
with open('config.json') as fh: data = fh.read()	with open('config.json') as fh: data = fh.read()	Correct.	Python
function test(): void {{ return 22; }}	function test(): number {{ return 22; }}	Return type mismatch.	TypeScript
String a = 'data';	String a = "data";	Double quotes.	Java
const z;	const z = 36;	Initialize const.	JavaScript
if (item = 88)	if (item == 88)	Use ==.	R
<div><p>value</div></p>	<div><p>value</p></div>	Nest properly.	HTML
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
if ($data = 78) {{}}	if ($data -eq 78) {{}}	Use -eq.	PowerShell
SELECT name role FROM products;	SELECT name, role FROM products;	Add comma.	SQL
class Order def method end end	class Order def method end end	Correct.	Ruby
'result' + 29	'result' + str(29)	Can't add int to string.	Python
<?php // code ?>	<?php // code ?>	Correct.	PHP
<hr></hr>	<hr>	Self-closing.	HTML
try {{ throw 'world'; }} catch(e) {{}}	try {{ throw new Error('world'); }} catch(e) {{}}	Throw Error objects.	JavaScript
[x*x for x in list if x > 88]	[x*x for x in list if x > 88]	Correct list comprehension.	Python
raise 'message'	raise Exception('message')	Raise needs an exception class.	Python
let num = 97; let num = 67;	let num = 97; num = 67;	Duplicate declaration.	JavaScript
<person age=75>	<person age="75">	Quote attribute.	XML
DELETE FROM users WHERE name=79	DELETE FROM users WHERE name=79;	Add semicolon.	SQL
function bar(z) print(z) end	function bar(z) print(z) end	Correct.	Lua
System.out.println('world')	System.out.println('world');	Add semicolon.	Java
var x int	var x int	Correct.	Go
while a > 86 a -= 1	while a > 86: a -= 1	Colon missing after while.	Python

val y = 'info'

val y = "info"

Double quotes.

Kotlin

Colon missing.

Python

UPDATE products SET age='test' WHERE role=35

UPDATE products SET age='test' WHERE role=35;

Add semicolon.

SQL

int* user = nullptr; *user=5;

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

Allocate memory.

C++

SELECT * FROM users WHRE id=16;

SELECT * FROM users WHERE id=16;

Fix WHERE.

SQL

val c: Int = 'test'

val c: String = 'test'

Fix type.

Kotlin

Use style attribute.

CSS

for i=1,2 do print(i) end

Correct.

Lua

const person:Person = {{name:'output'}};

const person:Person = {{name:'output', age:45}};

Add missing property.

TypeScript

local num = 13

Correct.

Lua

let mut z=8; let ref1=&mut z; let r2=&mut z;

let mut z=8; {{ let ref1=&mut z; }} let r2=&mut z;

Only one mutable borrow.

Rust

#content {{ color: #333; }}

Correct.

CSS

disp('output')

Correct.

MATLAB

if (index = 89) {{}}

if (index == 89) {{}}

Use ==.

Kotlin

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

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

Correct.

Dart

fn baz() -> i32 {{ 93 }}

Correct.

Rust

console.log('data'

console.log('data')

Close parenthesis.

JavaScript

let list=vec![92,37,40]; let primary=&list[0]; list.push(53);

let mut list=vec![92,37,40]; let primary=list[0]; list.push(53);

Copy instead of reference.

Rust

const result = 91; result = 96;

let result = 91; result = 96;

Cannot reassign const.

JavaScript

WHERE email = '33'

WHERE email = 33

Don't quote integer.

SQL

class Child Super:

class Child(Super):

Inheritance uses parentheses.

Python

Correct.

XML

x := 66

Correct.

Go

echo test data

echo 'test data'

Quote to prevent splitting.

Shell

def compute(temp): return temp + 1

Correct.

Python

$values[96] = 5;

if (isset($values[96])) $values[96] = 5;

Check existence.

PHP

print('world')

Correct.

R

function process(bar:string){{return bar;}} process(82);

function process(bar:string){{return bar;}} process('info');

Pass correct type.

TypeScript

item = result

item = 'result'

Quote strings.

Python

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

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

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

Add return type Unit.

Scala

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(76);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(76, () => console.log('listening'));

Add callback.

Node.js

if (foo = 19) {}

if (foo == 19) {}

Use ==.

Dart

println('data')

println("data")

Double quotes.

Scala

String name = 'test';

Correct.

Dart

Add alt text.

HTML

jwt.sign({{id:70}}, 'password');

jwt.sign({{id:70}}, 'password', {{expiresIn:'30m'}});

Add expiration.

Node.js

int[] items = new int[64]; items[64] = 5;

int[] items = new int[64]; if (64 < items.length) items[64] = 5;

Check bounds.

Java

let data: Int = 'data'

let data: String = 'data'

Fix type.

Swift

Write-Host 'data'

Correct.

PowerShell

Add comma.

JSON

if b = 64

if b == 64

Use ==.

Ruby

[77, 82, 18

[77, 82, 18]

Close bracket.

Ruby

int main() {{ return 0; }}

Correct.

C++

["message", 72]

Correct.

JSON

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

Correct.

Shell

Close td.

HTML

items.forEach(function(val) {{ console.log(val); }})

items.forEach((val) => {{ console.log(val); }})

Arrow functions are cleaner.

JavaScript

ArrayList list = new ArrayList();

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

Use generics.

Java

User.save();

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

Handle promise.

Node.js

def foo puts 'test' end

Correct.

Ruby

if ($a = 21)

if ($a == 21)

Use ==.

Perl

for (int i=0; i<78; i++) {{}}

Correct.

Java

if a > 86 puts 'output'

if a > 86 puts 'output' end

Add 'end'.

Ruby

<center>result</center>

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

Use CSS.

HTML

let z = 40; z += 1;

let mut z = 40; z += 1;

Need mut to modify.

Rust

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

{ "name": "info" }

Correct.

JSON

const http = require('http'); http.createServer((req,res) => res.end('test')).listen(38);

Correct.

Node.js

<user><desc>hello</desc><name>100</name></user

<user><desc>hello</desc><name>100</name></user>

Add closing >.

XML

let result: number | null = null; result.toFixed(96);

let result: number | null = null; if(result!==null) result.toFixed(96);

Null check.

TypeScript

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

b > 23 & x < 25

b > 23 and x < 25

Use 'and' not '&'.

Python

lambda x: x+1

Correct lambda.

Python

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

Correct.

PowerShell

cin >> foo cout << foo;

cin >> foo; cout << foo;

Add semicolon.

C++

compute

compute()

Add parentheses.

Swift

<br>

Self-closing.

HTML

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

Correct.

MATLAB

print 'output'

print('output')

print needs parentheses.

Python

if item > 15 print('world')

if item > 15: print('world')

Colon missing after if.

Python

List(15,17,61)

Correct.

Scala

cin >> z;

int z; cin >> z;

Declare variable.

C++

SELECT COUNT(*) FROM orders

SELECT COUNT(*) FROM orders;

Missing semicolon.

SQL

var temp int = 'world'

var temp string = 'world'

Type mismatch.

Go

Add name attribute.

HTML

with open('config.json') as fh: data = fh.read()

Correct.

Python

function test(): void {{ return 22; }}

function test(): number {{ return 22; }}

Return type mismatch.

TypeScript

String a = 'data';

String a = "data";

Double quotes.

Java

const z;

const z = 36;

Initialize const.

JavaScript

if (item = 88)

if (item == 88)

Use ==.

R

<div><p>value</div></p>

<div><p>value</p></div>

Nest properly.

HTML

Add rel for security.

HTML

if ($data = 78) {{}}

if ($data -eq 78) {{}}

Use -eq.

PowerShell

SELECT name role FROM products;

SELECT name, role FROM products;

Add comma.

SQL

class Order def method end end

Correct.

Ruby

'result' + 29

'result' + str(29)

Can't add int to string.

Python

<?php // code ?>

Correct.

PHP

<hr>

Self-closing.

HTML

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

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

Throw Error objects.

JavaScript

[x*x for x in list if x > 88]

Correct list comprehension.

Python

raise 'message'

raise Exception('message')

Raise needs an exception class.

Python

let num = 97; let num = 67;

let num = 97; num = 67;

Duplicate declaration.

JavaScript

Quote attribute.

XML

DELETE FROM users WHERE name=79

DELETE FROM users WHERE name=79;

Add semicolon.

SQL

function bar(z) print(z) end

Correct.

Lua

System.out.println('world')

System.out.println('world');

Add semicolon.

Java

var x int

Correct.

Go

while a > 86 a -= 1

while a > 86: a -= 1

Colon missing after while.

Python