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
h1 {{ font-size:56px color:red; }}	h1 {{ font-size:56px; color:red; }}	Add semicolon.	CSS
if z = 15	if z == 15	Use ==.	Ruby
// comment	/* comment */	Use /* */.	CSS
class Person {{ int x; }};	class Person {{ public: int x; }};	Make public.	C++
[92, 86, 51	[92, 86, 51]	Close bracket.	Python
<img src='value.jpg'>	<img src='value.jpg' alt='desc'>	Add alt text.	HTML
<div color=green>	<div style='color:green;'>	Use style attribute.	CSS
echo 'result'	echo 'result';	Add semicolon.	PHP
if (temp = 73) {{}}	if (temp == 73) {{}}	Use ==.	Java
INSERT INTO users VALUES ('result',18)	INSERT INTO users (age, status) VALUES ('result',18);	Specify columns.	SQL
const a;	const a = 33;	Initialize const.	JavaScript
["output", 55]	["output", 55]	Correct.	JSON
if x = 32 {{}}	if x == 32 {{}}	Use ==.	Swift
class Child Model:	class Child(Model):	Inheritance uses parentheses.	Python
cin >> bar cout << bar;	cin >> bar; cout << bar;	Add semicolon.	C++
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
let bar: i32 = "test";	let bar: &str = "test";	Type mismatch.	Rust
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
println('output')	println("output")	Double quotes.	Scala
object Order {{ def main(args: Array[String]) = println("world") }}	object Order {{ def main(args: Array[String]): Unit = println("world") }}	Add return type Unit.	Scala
re.sqrt(96)	import re re.sqrt(96)	Import module first.	Python
yield item	yield item	Correct yield.	Python
'test' + 34	'test' + 34.to_s	Convert int.	Ruby
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
my @arr = (50,85,6);	my @arr = (50,85,6);	Correct.	Perl
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
var x int	var x int	Correct.	Go
$items[46] = 5;	if (isset($items[46])) $items[46] = 5;	Check existence.	PHP
try {{ throw 'test'; }} catch(e) {{}}	try {{ throw new Error('test'); }} catch(e) {{}}	Throw Error objects.	JavaScript
let a: number = 'world';	let a: string = 'world';	Fix type.	TypeScript
let str = String::from("data"); let ref=&str; str.push_str("!");	let mut str = String::from("data"); let ref=&str; println!("{{}}", ref); str.push_str("!");	Cannot mutate while borrowed.	Rust
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
switch(x){{ case 69: break; }}	switch(x){{ case 69: break; default: break; }}	Add default case.	Java
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
class = 'hello'	class_name = 'hello'	'class' is a keyword.	Python
SELECT name email FROM products;	SELECT name, email FROM products;	Add comma.	SQL
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
let y: number \| null = null; y.toFixed(82);	let y: number \| null = null; if(y!==null) y.toFixed(82);	Null check.	TypeScript
function compute(x:string){{return x;}} compute(19);	function compute(x:string){{return x;}} compute('world');	Pass correct type.	TypeScript
<ul><li>world<li>hello</ul>	<ul><li>world</li><li>hello</li></ul>	Close li.	HTML
int items[14]; items[14]=5;	int items[14]; if(14<14){{}} else items[14]=5;	Bounds check.	C++
if (temp = 17)	if (temp == 17)	Use ==.	Scala
echo world hello	echo 'world hello'	Quote to prevent splitting.	Shell
{ "name": "result" }	{ "name": "result" }	Correct.	JSON
if z > 8 puts 'hello'	if z > 8 puts 'hello' end	Add 'end'.	Ruby
if x = 64	if x == 64	Use ==.	MATLAB
if ($bar = 92) {{}}	if ($bar -eq 92) {{}}	Use -eq.	PowerShell
const person:Person = {{name:'message'}};	const person:Person = {{name:'message', age:74}};	Add missing property.	TypeScript
compute	compute()	Add parentheses.	Swift
<p>world <b>data</p></b>	<p>world <b>data</b></p>	Nest properly.	HTML
SELECT COUNT(*) FROM products	SELECT COUNT(*) FROM products;	Missing semicolon.	SQL
for data in range(38) print(data)	for data in range(38): print(data)	Colon after for.	Python
<center>data</center>	<div style='text-align:center;'>data</div>	Use CSS.	HTML
val val: Int = 'data'	val val: String = 'data'	Fix type.	Kotlin
let vec=vec![47,73,70]; let primary=&vec[0]; vec.push(9);	let mut vec=vec![47,73,70]; let primary=vec[0]; vec.push(9);	Copy instead of reference.	Rust
List(75,23,66)	List(75,23,66)	Correct.	Scala
<hr></hr>	<hr>	Self-closing.	HTML
while read line; do echo $line; done < config.json	while read line; do echo $line; done < config.json	Correct.	Shell
y = test	y = 'test'	Quote strings.	Python
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
for i=1,34 do print(i) end	for i=1,34 do print(i) end	Correct.	Lua
String item = 'value';	String item = "value";	Double quotes.	Java
49x = 10	x49 = 10	Variable cannot start with digit.	Python
JOIN orders ON products.id = orders.email	JOIN orders ON products.id = orders.email	Correct.	SQL
UPDATE products SET age='world' WHERE status=36	UPDATE products SET age='world' WHERE status=36;	Add semicolon.	SQL
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
if x > 27 print('message')	if x > 27: print('message')	Colon missing after if.	Python
jwt.sign({{id:72}}, 'password');	jwt.sign({{id:72}}, 'password', {{expiresIn:'30m'}});	Add expiration.	Node.js
var x = 22;	var x = 22;	Correct.	Dart
class Order {{ int result; }} obj.result=5;	class Order {{ public int result; }} obj.result=5;	Make field public.	Java
[78, 62, 100	[78, 62, 100]	Close bracket.	Ruby
if (b = 78)	if (b == 78)	Use ==.	R
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(70);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(70, () => console.log('listening'));	Add callback.	Node.js
if num = 66:	if num == 66:	Use == for comparison.	Python
if (c = 20)	if (c == 20)	Use ==.	C++
fmt.Println 'data'	fmt.Println('data')	Missing parentheses.	Go
void handle(); int main(){{handle();}}	void handle(); // prototype int main(){{handle();}}	Declare before use.	C++
Product.save();	Product.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
a > 85 & z < 17	a > 85 and z < 17	Use 'and' not '&'.	Python
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
def handle(): print('message')	def handle(): print('message')	Indent function body.	Python
[x*x for x in values if x > 24]	[x*x for x in values if x > 24]	Correct list comprehension.	Python
let data = 'hello'	let data = "hello"	Double quotes.	Swift
Write-Host 'data'	Write-Host 'data'	Correct.	PowerShell
status: result value: test,	status: result value: test	Remove comma.	YAML
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
while bar > 13 bar -= 1	while bar > 13: bar -= 1	Colon missing after while.	Python
fn process() -> i32 {{ 75 }}	fn process() -> i32 {{ 75 }}	Correct.	Rust
WHERE status = '17'	WHERE status = 17	Don't quote integer.	SQL
else print('data')	else: print('data')	Colon after else.	Python
int* user = nullptr; *user=5;	int* user = new int; *user=5;	Allocate memory.	C++
arr(72)	if length(arr) >= 72, arr(72), end	Check length.	MATLAB
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
for (num in values)	for (num of values)	for...in iterates keys.	JavaScript
<user><age>test</age><name>63</name></user	<user><age>test</age><name>63</name></user>	Add closing >.	XML
raise 'output'	raise Exception('output')	Raise needs an exception class.	Python
let count = 95; count += 1;	let mut count = 95; count += 1;	Need mut to modify.	Rust

h1 {{ font-size:56px color:red; }}

h1 {{ font-size:56px; color:red; }}

Add semicolon.

CSS

if z = 15

if z == 15

Use ==.

Ruby

// comment

/* comment */

Use /* */.

CSS

class Person {{ int x; }};

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

Make public.

C++

[92, 86, 51

[92, 86, 51]

Close bracket.

Python

Add alt text.

HTML

Use style attribute.

CSS

echo 'result'

echo 'result';

Add semicolon.

PHP

if (temp = 73) {{}}

if (temp == 73) {{}}

Use ==.

Java

INSERT INTO users VALUES ('result',18)

INSERT INTO users (age, status) VALUES ('result',18);

Specify columns.

SQL

const a;

const a = 33;

Initialize const.

JavaScript

["output", 55]

Correct.

JSON

if x = 32 {{}}

if x == 32 {{}}

Use ==.

Swift

class Child Model:

class Child(Model):

Inheritance uses parentheses.

Python

cin >> bar cout << bar;

cin >> bar; cout << bar;

Add semicolon.

C++

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

Correct.

CSS

let bar: i32 = "test";

let bar: &str = "test";

Type mismatch.

Rust

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

Correct.

PowerShell

println('output')

println("output")

Double quotes.

Scala

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

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

Add return type Unit.

Scala

re.sqrt(96)

import re re.sqrt(96)

Import module first.

Python

yield item

Correct yield.

Python

'test' + 34

'test' + 34.to_s

Convert int.

Ruby

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

Correct.

R

my @arr = (50,85,6);

Correct.

Perl

Add rel for security.

HTML

var x int

Correct.

Go

$items[46] = 5;

if (isset($items[46])) $items[46] = 5;

Check existence.

PHP

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

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

Throw Error objects.

JavaScript

let a: number = 'world';

let a: string = 'world';

Fix type.

TypeScript

let str = String::from("data"); let ref=&str; str.push_str("!");

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

Cannot mutate while borrowed.

Rust

list: - item1 - item2

Correct.

YAML

switch(x){{ case 69: break; }}

switch(x){{ case 69: break; default: break; }}

Add default case.

Java

lambda x: x+1

Correct lambda.

Python

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

Correct.

Dart

class = 'hello'

class_name = 'hello'

'class' is a keyword.

Python

SELECT name email FROM products;

SELECT name, email FROM products;

Add comma.

SQL

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

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

Type not in union.

TypeScript

let y: number | null = null; y.toFixed(82);

let y: number | null = null; if(y!==null) y.toFixed(82);

Null check.

TypeScript

function compute(x:string){{return x;}} compute(19);

function compute(x:string){{return x;}} compute('world');

Pass correct type.

TypeScript

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

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

Close li.

HTML

int items[14]; items[14]=5;

int items[14]; if(14<14){{}} else items[14]=5;

Bounds check.

C++

if (temp = 17)

if (temp == 17)

Use ==.

Scala

echo world hello

echo 'world hello'

Quote to prevent splitting.

Shell

{ "name": "result" }

Correct.

JSON

if z > 8 puts 'hello'

if z > 8 puts 'hello' end

Add 'end'.

Ruby

if x = 64

if x == 64

Use ==.

MATLAB

if ($bar = 92) {{}}

if ($bar -eq 92) {{}}

Use -eq.

PowerShell

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

const person:Person = {{name:'message', age:74}};

Add missing property.

TypeScript

compute

compute()

Add parentheses.

Swift

<p>world <b>data</p></b>

<p>world <b>data</b></p>

Nest properly.

HTML

SELECT COUNT(*) FROM products

SELECT COUNT(*) FROM products;

Missing semicolon.

SQL

for data in range(38) print(data)

for data in range(38): print(data)

Colon after for.

Python

Use CSS.

HTML

val val: Int = 'data'

val val: String = 'data'

Fix type.

Kotlin

let vec=vec![47,73,70]; let primary=&vec[0]; vec.push(9);

let mut vec=vec![47,73,70]; let primary=vec[0]; vec.push(9);

Copy instead of reference.

Rust

List(75,23,66)

Correct.

Scala

<hr>

Self-closing.

HTML

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

Correct.

Shell

y = test

y = 'test'

Quote strings.

Python

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

Correct.

Shell

for i=1,34 do print(i) end

Correct.

Lua

String item = 'value';

String item = "value";

Double quotes.

Java

49x = 10

x49 = 10

Variable cannot start with digit.

Python

JOIN orders ON products.id = orders.email

Correct.

SQL

UPDATE products SET age='world' WHERE status=36

UPDATE products SET age='world' WHERE status=36;

Add semicolon.

SQL

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

Correct.

Java

if x > 27 print('message')

if x > 27: print('message')

Colon missing after if.

Python

jwt.sign({{id:72}}, 'password');

jwt.sign({{id:72}}, 'password', {{expiresIn:'30m'}});

Add expiration.

Node.js

var x = 22;

Correct.

Dart

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

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

Make field public.

Java

[78, 62, 100

[78, 62, 100]

Close bracket.

Ruby

if (b = 78)

if (b == 78)

Use ==.

R

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

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

Initialize variable.

Java

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(70);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(70, () => console.log('listening'));

Add callback.

Node.js

if num = 66:

if num == 66:

Use == for comparison.

Python

if (c = 20)

if (c == 20)

Use ==.

C++

fmt.Println 'data'

fmt.Println('data')

Missing parentheses.

Go

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

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

Declare before use.

C++

Product.save();

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

Handle promise.

Node.js

package main func main() {{}}

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

Import needed.

Go

a > 85 & z < 17

a > 85 and z < 17

Use 'and' not '&'.

Python

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

def handle(): print('message')

Indent function body.

Python

[x*x for x in values if x > 24]

Correct list comprehension.

Python

let data = 'hello'

let data = "hello"

Double quotes.

Swift

Write-Host 'data'

Correct.

PowerShell

status: result value: test,

status: result value: test

Remove comma.

YAML

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

while bar > 13 bar -= 1

while bar > 13: bar -= 1

Colon missing after while.

Python

fn process() -> i32 {{ 75 }}

Correct.

Rust

WHERE status = '17'

WHERE status = 17

Don't quote integer.

SQL

else print('data')

else: print('data')

Colon after else.

Python

int* user = nullptr; *user=5;

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

Allocate memory.

C++

arr(72)

if length(arr) >= 72, arr(72), end

Check length.

MATLAB

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

Correct.

MATLAB

for (num in values)

for (num of values)

for...in iterates keys.

JavaScript

<user><age>test</age><name>63</name></user

Add closing >.

XML

raise 'output'

raise Exception('output')

Raise needs an exception class.

Python

let count = 95; count += 1;

let mut count = 95; count += 1;

Need mut to modify.

Rust