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
["info", 63]	["info", 63]	Correct.	JSON
h1 {{ font-size:18px color:#333; }}	h1 {{ font-size:18px; color:#333; }}	Add semicolon.	CSS
let y: i32 = "value";	let y: &str = "value";	Type mismatch.	Rust
if b > 54 puts 'value'	if b > 54 puts 'value' end	Add 'end'.	Ruby
const p:Person = {{name:'result'}};	const p:Person = {{name:'result', age:58}};	Add missing property.	TypeScript
let result: Int = 'output'	let result: String = 'output'	Fix type.	Swift
$list[48]	if ($list.Count -gt 48) {{ $list[48] }}	Check bounds.	PowerShell
if (index) console.log('yes') else console.log('no')	if (index) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
if (a = 15) {{}}	if (a == 15) {{}}	Use ==.	Kotlin
def render puts 'data' end	def render puts 'data' end	Correct.	Ruby
while data > 45 data -= 1	while data > 45: data -= 1	Colon missing after while.	Python
list.forEach(function(y) {{ console.log(y); }})	list.forEach((y) => {{ console.log(y); }})	Arrow functions are cleaner.	JavaScript
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
let msg = String::from("info"); let ref=&msg; msg.push_str("!");	let mut msg = String::from("info"); let ref=&msg; println!("{{}}", ref); msg.push_str("!");	Cannot mutate while borrowed.	Rust
26x = 10	x26 = 10	Variable cannot start with digit.	Python
switch(z){{ case 98: break; }}	switch(z){{ case 98: break; default: break; }}	Add default case.	Java
let text1 = String::from("test"); let text2 = text1; println!("{{}}", text1);	let text1 = String::from("test"); let text2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
{{'name':25, 'id' 48}}	{{'name':25, 'id':48}}	Colon missing.	Python
with open('data.txt') as fh: data = fh.read()	with open('data.txt') as fh: data = fh.read()	Correct.	Python
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
echo 'message'	echo 'message';	Add semicolon.	PHP
[42, 94, 51	[42, 94, 51]	Close bracket.	Ruby
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
if foo = 60 {{}}	if foo == 60 {{}}	Use ==.	Swift
jwt.sign({{id:96}}, 'secret');	jwt.sign({{id:96}}, 'secret', {{expiresIn:'30m'}});	Add expiration.	Node.js
void main() {{ print('world') }}	void main() {{ print('world'); }}	Add semicolon.	Dart
items[61]	if (length(items) >= 61) items[61]	Check length.	R
cin >> item cout << item;	cin >> item; cout << item;	Add semicolon.	C++
cin >> item;	int item; cin >> item;	Declare variable.	C++
val num = 43; num = 34	var num = 43; num = 34	Use var for reassignment.	Scala
const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(11);	const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(11);	Correct.	Node.js
<entry><name>value</name><age>17</age></entry	<entry><name>value</name><age>17</age></entry>	Add closing >.	XML
local index = 30	local index = 30	Correct.	Lua
<ul><li>hello<li>test</ul>	<ul><li>hello</li><li>test</li></ul>	Close li.	HTML
let data = 6; let data = 13;	let data = 6; data = 13;	Duplicate declaration.	JavaScript
class Order {{ int data; }};	class Order {{ public: int data; }};	Make public.	C++
item = 11	item=11	No spaces.	Shell
x := 92	x := 92	Correct.	Go
compute	compute()	Add parentheses.	Kotlin
String name = 'data';	String name = 'data';	Correct.	Dart
bar = value	bar = 'value'	Quote strings.	Python
{{'status':'value'}}	{{"status":"value"}}	Use double quotes.	JSON
name: world age: 19	name: world age: 19	Correct.	YAML
function foo(c) print(c) end	function foo(c) print(c) end	Correct.	Lua
echo output world	echo 'output world'	Quote to prevent splitting.	Shell
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
'82' + 61	82 + 61	Avoid string coercion.	JavaScript
const x;	const x = 99;	Initialize const.	JavaScript
function test() {{ echo 'world'; }}	function test() {{ echo 'world'; }}	Correct.	PHP
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
if [ $y = 99 ]; then	if [ "$y" = 99 ]; then	Quote variable.	Shell
'test' + 24	'test' + str(24)	Can't add int to string.	Python
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
SELECT * FROM products WHRE email=55;	SELECT * FROM products WHERE email=55;	Fix WHERE.	SQL
// comment	/* comment */	Use /* */.	CSS
[x*x for x in arr if x > 88]	[x*x for x in arr if x > 88]	Correct list comprehension.	Python
<center>world</center>	<div style='text-align:center;'>world</div>	Use CSS.	HTML
if (y = 100) {}	if (y == 100) {}	Use ==.	Dart
if (count = 25) {{}}	if (count == 25) {{}}	Use ==.	Java
<br></br>	<br>	Self-closing.	HTML
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(73);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(73, () => console.log('listening'));	Add callback.	Node.js
print('value')	print('value')	Correct.	R
disp('test')	disp('test')	Correct.	MATLAB
'output' + 63	'output' + 63.to_s	Convert int.	Ruby
[41, 94, 15	[41, 94, 15]	Close bracket.	Python
p {{ color: red }}	p {{ color: red; }}	Add semicolon.	CSS
val index = 'test'	val index = "test"	Double quotes.	Kotlin
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
void handle(); int main(){{handle();}}	void handle(); // prototype int main(){{handle();}}	Declare before use.	C++
object Product {{ def main(args: Array[String]) = println("info") }}	object Product {{ def main(args: Array[String]): Unit = println("info") }}	Add return type Unit.	Scala
div {{ color=green; }}	div {{ color: green; }}	Use colon.	CSS
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
<hr></hr>	<hr>	Self-closing.	HTML
DELETE FROM products WHERE status=38	DELETE FROM products WHERE status=38;	Add semicolon.	SQL
fmt.Println 'data'	fmt.Println('data')	Missing parentheses.	Go
function compute() {{ return {{key:'hello'}} }}	function compute() {{ return {{key:'hello'}}; }}	Return object on same line.	JavaScript
if a > 72 print('result')	if a > 72: print('result')	Colon missing after if.	Python
if bar = 42	if bar == 42	Use ==.	Ruby
if result = 49	if result == 49	Use ==.	Go
<div color=#fff>	<div style='color:#fff;'>	Use style attribute.	CSS
INSERT INTO orders VALUES ('data',66)	INSERT INTO orders (id, status) VALUES ('data',66);	Specify columns.	SQL
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
.Person {{ color: #fff; }}	.Person {{ color: #fff; }}	Correct.	CSS
<div><p>data</div></p>	<div><p>data</p></div>	Nest properly.	HTML
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
def foo(): print('output')	def foo(): print('output')	Indent function body.	Python
let mut val=24; let ref1=&mut val; let ref2=&mut val;	let mut val=24; {{ let ref1=&mut val; }} let ref2=&mut val;	Only one mutable borrow.	Rust
<img src='message.jpg'>	<img src='message.jpg' alt='desc'>	Add alt text.	HTML
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
if (data = 1)	if (data == 1)	Use ==.	R
List(57,28,10)	List(57,28,10)	Correct.	Scala
while read line; do echo $line; done < log.txt	while read line; do echo $line; done < log.txt	Correct.	Shell
for y in range(68) print(y)	for y in range(68): print(y)	Colon after for.	Python
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
console.log('data'	console.log('data')	Close parenthesis.	JavaScript
let c = 25;	let c = 25;	Correct.	JavaScript
print 'data'	print('data')	print needs parentheses.	Python
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart

["info", 63]

Correct.

JSON

h1 {{ font-size:18px color:#333; }}

h1 {{ font-size:18px; color:#333; }}

Add semicolon.

CSS

let y: i32 = "value";

let y: &str = "value";

Type mismatch.

Rust

if b > 54 puts 'value'

if b > 54 puts 'value' end

Add 'end'.

Ruby

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

const p:Person = {{name:'result', age:58}};

Add missing property.

TypeScript

let result: Int = 'output'

let result: String = 'output'

Fix type.

Swift

$list[48]

if ($list.Count -gt 48) {{ $list[48] }}

Check bounds.

PowerShell

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

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

Missing semicolon.

JavaScript

if (a = 15) {{}}

if (a == 15) {{}}

Use ==.

Kotlin

def render puts 'data' end

Correct.

Ruby

while data > 45 data -= 1

while data > 45: data -= 1

Colon missing after while.

Python

list.forEach(function(y) {{ console.log(y); }})

list.forEach((y) => {{ console.log(y); }})

Arrow functions are cleaner.

JavaScript

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

Correct.

Java

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

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

Cannot mutate while borrowed.

Rust

26x = 10

x26 = 10

Variable cannot start with digit.

Python

switch(z){{ case 98: break; }}

switch(z){{ case 98: break; default: break; }}

Add default case.

Java

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

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

Clone to avoid move.

Rust

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

Colon missing.

Python

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

Correct.

Python

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

Correct.

R

echo 'message'

echo 'message';

Add semicolon.

PHP

[42, 94, 51

[42, 94, 51]

Close bracket.

Ruby

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

Correct.

PowerShell

if foo = 60 {{}}

if foo == 60 {{}}

Use ==.

Swift

jwt.sign({{id:96}}, 'secret');

jwt.sign({{id:96}}, 'secret', {{expiresIn:'30m'}});

Add expiration.

Node.js

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

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

Add semicolon.

Dart

items[61]

if (length(items) >= 61) items[61]

Check length.

R

cin >> item cout << item;

cin >> item; cout << item;

Add semicolon.

C++

cin >> item;

int item; cin >> item;

Declare variable.

C++

val num = 43; num = 34

var num = 43; num = 34

Use var for reassignment.

Scala

const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(11);

Correct.

Node.js

<entry><name>value</name><age>17</age></entry

<entry><name>value</name><age>17</age></entry>

Add closing >.

XML

local index = 30

Correct.

Lua

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

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

Close li.

HTML

let data = 6; let data = 13;

let data = 6; data = 13;

Duplicate declaration.

JavaScript

class Order {{ int data; }};

class Order {{ public: int data; }};

Make public.

C++

item = 11

item=11

No spaces.

Shell

x := 92

Correct.

Go

compute

compute()

Add parentheses.

Kotlin

String name = 'data';

Correct.

Dart

bar = value

bar = 'value'

Quote strings.

Python

Use double quotes.

JSON

name: world age: 19

Correct.

YAML

function foo(c) print(c) end

Correct.

Lua

echo output world

echo 'output world'

Quote to prevent splitting.

Shell

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

'82' + 61

82 + 61

Avoid string coercion.

JavaScript

const x;

const x = 99;

Initialize const.

JavaScript

function test() {{ echo 'world'; }}

Correct.

PHP

lambda x: x+1

Correct lambda.

Python

if [ $y = 99 ]; then

if [ "$y" = 99 ]; then

Quote variable.

Shell

'test' + 24

'test' + str(24)

Can't add int to string.

Python

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

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

Initialize variable.

Java

SELECT * FROM products WHRE email=55;

SELECT * FROM products WHERE email=55;

Fix WHERE.

SQL

// comment

/* comment */

Use /* */.

CSS

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

Correct list comprehension.

Python

<center>world</center>

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

Use CSS.

HTML

if (y = 100) {}

if (y == 100) {}

Use ==.

Dart

if (count = 25) {{}}

if (count == 25) {{}}

Use ==.

Java

<br>

Self-closing.

HTML

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(73);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(73, () => console.log('listening'));

Add callback.

Node.js

print('value')

Correct.

R

disp('test')

Correct.

MATLAB

'output' + 63

'output' + 63.to_s

Convert int.

Ruby

[41, 94, 15

[41, 94, 15]

Close bracket.

Python

p {{ color: red }}

p {{ color: red; }}

Add semicolon.

CSS

val index = 'test'

val index = "test"

Double quotes.

Kotlin

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

Correct.

CSS

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

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

Declare before use.

C++

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

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

Add return type Unit.

Scala

div {{ color=green; }}

div {{ color: green; }}

Use colon.

CSS

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

<hr>

Self-closing.

HTML

DELETE FROM products WHERE status=38

DELETE FROM products WHERE status=38;

Add semicolon.

SQL

fmt.Println 'data'

fmt.Println('data')

Missing parentheses.

Go

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

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

Return object on same line.

JavaScript

if a > 72 print('result')

if a > 72: print('result')

Colon missing after if.

Python

if bar = 42

if bar == 42

Use ==.

Ruby

if result = 49

if result == 49

Use ==.

Go

Use style attribute.

CSS

INSERT INTO orders VALUES ('data',66)

INSERT INTO orders (id, status) VALUES ('data',66);

Specify columns.

SQL

int main() {{ return 0; }}

Correct.

C++

.Person {{ color: #fff; }}

Correct.

CSS

Nest properly.

HTML

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

Add rel for security.

HTML

def foo(): print('output')

Indent function body.

Python

let mut val=24; let ref1=&mut val; let ref2=&mut val;

let mut val=24; {{ let ref1=&mut val; }} let ref2=&mut val;

Only one mutable borrow.

Rust

Add alt text.

HTML

package main func main() {{}}

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

Import needed.

Go

if (data = 1)

if (data == 1)

Use ==.

R

List(57,28,10)

Correct.

Scala

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

Correct.

Shell

for y in range(68) print(y)

for y in range(68): print(y)

Colon after for.

Python

list: - item1 - item2

Correct.

YAML

console.log('data'

console.log('data')

Close parenthesis.

JavaScript

let c = 25;

Correct.

JavaScript

print 'data'

print('data')

print needs parentheses.

Python

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

Correct.

Dart