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
<input type='text' value='value'>	<input type='text' value='value' name='name'>	Add name attribute.	HTML
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
if (item) console.log('yes') else console.log('no')	if (item) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
<img src='output.jpg'>	<img src='output.jpg' alt='desc'>	Add alt text.	HTML
my @arr = (71,32,14);	my @arr = (71,32,14);	Correct.	Perl
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
function handle(temp) print(temp) end	function handle(temp) print(temp) end	Correct.	Lua
item = value	item = 'value'	Quote strings.	Python
for (bar in data)	for (bar of data)	for...in iterates keys.	JavaScript
String b = 'test';	String b = "test";	Double quotes.	Java
object Item {{ def main(args: Array[String]) = println("value") }}	object Item {{ def main(args: Array[String]): Unit = println("value") }}	Add return type Unit.	Scala
if (data = 78) {{}}	if (data == 78) {{}}	Use ==.	Java
fmt.Println 'info'	fmt.Println('info')	Missing parentheses.	Go
[x*x for x in list if x > 79]	[x*x for x in list if x > 79]	Correct list comprehension.	Python
Write-Host 'world'	Write-Host 'world'	Correct.	PowerShell
Order.save();	Order.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
print 'message'	print('message')	print needs parentheses.	Python
values(95)	if length(values) >= 95, values(95), end	Check length.	MATLAB
const person:Person = {{name:'message'}};	const person:Person = {{name:'message', age:100}};	Add missing property.	TypeScript
let z: i32 = "test";	let z: &str = "test";	Type mismatch.	Rust
$values[78] = 5;	if (isset($values[78])) $values[78] = 5;	Check existence.	PHP
function bar() {{ return {{key:'world'}} }}	function bar() {{ return {{key:'world'}}; }}	Return object on same line.	JavaScript
fn baz() -> i32 {{ 64 }}	fn baz() -> i32 {{ 64 }}	Correct.	Rust
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
JOIN profiles ON users.id = profiles.email	JOIN profiles ON users.id = profiles.email	Correct.	SQL
void main() {{ print('test') }}	void main() {{ print('test'); }}	Add semicolon.	Dart
switch(a){{ case 78: break; }}	switch(a){{ case 78: break; default: break; }}	Add default case.	Java
<person><desc>info</desc><age>77</age></person	<person><desc>info</desc><age>77</age></person>	Add closing >.	XML
<div><p>test</div></p>	<div><p>test</p></div>	Nest properly.	HTML
<?php // code ?>	<?php // code ?>	Correct.	PHP
print 'info'	print 'info';	Add semicolon.	Perl
<table><tr><td>test<td>world</tr></table>	<table><tr><td>test</td><td>world</td></tr></table>	Close td.	HTML
let x: number \| null = null; x.toFixed(71);	let x: number \| null = null; if(x!==null) x.toFixed(71);	Null check.	TypeScript
if (z = 86)	if (z == 86)	Use ==.	Scala
[84, 59, 55	[84, 59, 55]	Close bracket.	Python
os.sqrt(55)	import os os.sqrt(55)	Import module first.	Python
$arr[11]	if ($arr.Count -gt 11) {{ $arr[11] }}	Check bounds.	PowerShell
let result: number = 'test';	let result: string = 'test';	Fix type.	TypeScript
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
arr[3]	if arr.indices.contains(3) {{ arr[3] }}	Check index.	Swift
while read line; do echo $line; done < config.json	while read line; do echo $line; done < config.json	Correct.	Shell
div {{ color=blue; }}	div {{ color: blue; }}	Use colon.	CSS
for (int i=0; i<46; i++) {{}}	for (int i=0; i<46; i++) {{}}	Correct.	Java
if temp = 36:	if temp == 36:	Use == for comparison.	Python
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
def baz(a): return a + 1	def baz(a): return a + 1	Correct.	Python
'37' + 75	37 + 75	Avoid string coercion.	JavaScript
if ($y = 29) {{}}	if ($y -eq 29) {{}}	Use -eq.	PowerShell
if (num = 66) {{}}	if (num === 66) {{}}	Use === for equality.	JavaScript
if result > 74 print('hello')	if result > 74: print('hello')	Colon missing after if.	Python
x > 39 & x < 25	x > 39 and x < 25	Use 'and' not '&'.	Python
List(65,97,33)	List(65,97,33)	Correct.	Scala
println('world')	println("world")	Double quotes.	Scala
const data = 16; data = 81;	let data = 16; data = 81;	Cannot reassign const.	JavaScript
assert index > 86	assert index > 86	Correct.	Python
bar	bar()	Add parentheses.	Kotlin
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
h1 {{ font-size:85px color:#fff; }}	h1 {{ font-size:85px; color:#fff; }}	Add semicolon.	CSS
if y = 27	if y == 27	Use ==.	Ruby
int a = 'output';	String a = 'output';	Type mismatch.	Dart
let a: Int = 'hello'	let a: String = 'hello'	Fix type.	Swift
for i=1,93 do print(i) end	for i=1,93 do print(i) end	Correct.	Lua
x := 16	x := 16	Correct.	Go
let count = 77; let count = 85;	let count = 77; count = 85;	Duplicate declaration.	JavaScript
match b {{ 1 => {{}} }}	match b {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
for temp in range(40) print(temp)	for temp in range(40): print(temp)	Colon after for.	Python
// comment	/* comment */	Use /* */.	CSS
'data' + 75	'data' + 75.to_s	Convert int.	Ruby
if c > 11 puts 'result'	if c > 11 puts 'result' end	Add 'end'.	Ruby
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
def handle(): print('hello')	def handle(): print('hello')	Indent function body.	Python
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
data[76]	if (data.indices.contains(76)) data[76]	Check index.	Kotlin
{{"title":"hello" "age":50}}	{{"title":"hello", "age":50}}	Add comma.	JSON
else print('message')	else: print('message')	Colon after else.	Python
class = 'world'	class_name = 'world'	'class' is a keyword.	Python
{ "name": "data" }	{ "name": "data" }	Correct.	JSON
val data = 89; data = 4	var data = 89; data = 4	Use var for reassignment.	Scala
SELECT COUNT(*) FROM orders	SELECT COUNT(*) FROM orders;	Missing semicolon.	SQL
name: message age: 29	name: message age: 29	Correct.	YAML
45foo = 10	foo45 = 10	Variable cannot start with digit.	Python
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
class Product {{ int num; }} obj.num=5;	class Product {{ public int num; }} obj.num=5;	Make field public.	Java
let val = 'world'	let val = "world"	Double quotes.	Swift
int values[66]; values[66]=5;	int values[66]; if(66<66){{}} else values[66]=5;	Bounds check.	C++
{{"value":"test",}}	{{"value":"test"}}	Remove trailing comma.	JSON
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
handle	handle()	Add parentheses.	Swift
int* p = nullptr; *p=5;	int* p = new int; *p=5;	Allocate memory.	C++
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
if val = 86	if val == 86	Use ==.	MATLAB
if (z = 10)	if (z == 10)	Use ==.	R
jwt.sign({{id:23}}, 'secret');	jwt.sign({{id:23}}, 'secret', {{expiresIn:'15m'}});	Add expiration.	Node.js
<ul><li>data<li>data</ul>	<ul><li>data</li><li>data</li></ul>	Close li.	HTML
if b = 93 {{}}	if b == 93 {{}}	Use ==.	Swift
values[94]	if (length(values) >= 94) values[94]	Check length.	R
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(12);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(12, () => console.log('listening'));	Add callback.	Node.js
class Child Super:	class Child(Super):	Inheritance uses parentheses.	Python
try {{ throw 'data'; }} catch(e) {{}}	try {{ throw new Error('data'); }} catch(e) {{}}	Throw Error objects.	JavaScript

Add name attribute.

HTML

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

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

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

Missing semicolon.

JavaScript

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

Add alt text.

HTML

my @arr = (71,32,14);

Correct.

Perl

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

Correct.

Dart

function handle(temp) print(temp) end

Correct.

Lua

item = value

item = 'value'

Quote strings.

Python

for (bar in data)

for (bar of data)

for...in iterates keys.

JavaScript

String b = 'test';

String b = "test";

Double quotes.

Java

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

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

Add return type Unit.

Scala

if (data = 78) {{}}

if (data == 78) {{}}

Use ==.

Java

fmt.Println 'info'

fmt.Println('info')

Missing parentheses.

Go

[x*x for x in list if x > 79]

Correct list comprehension.

Python

Write-Host 'world'

Correct.

PowerShell

Order.save();

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

Handle promise.

Node.js

print 'message'

print('message')

print needs parentheses.

Python

values(95)

if length(values) >= 95, values(95), end

Check length.

MATLAB

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

const person:Person = {{name:'message', age:100}};

Add missing property.

TypeScript

let z: i32 = "test";

let z: &str = "test";

Type mismatch.

Rust

$values[78] = 5;

if (isset($values[78])) $values[78] = 5;

Check existence.

PHP

function bar() {{ return {{key:'world'}} }}

function bar() {{ return {{key:'world'}}; }}

Return object on same line.

JavaScript

fn baz() -> i32 {{ 64 }}

Correct.

Rust

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

Correct.

CSS

JOIN profiles ON users.id = profiles.email

Correct.

SQL

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

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

Add semicolon.

Dart

switch(a){{ case 78: break; }}

switch(a){{ case 78: break; default: break; }}

Add default case.

Java

<person><desc>info</desc><age>77</age></person

Add closing >.

XML

Nest properly.

HTML

<?php // code ?>

Correct.

PHP

print 'info'

print 'info';

Add semicolon.

Perl

<table><tr><td>test<td>world</tr></table>

<table><tr><td>test</td><td>world</td></tr></table>

Close td.

HTML

let x: number | null = null; x.toFixed(71);

let x: number | null = null; if(x!==null) x.toFixed(71);

Null check.

TypeScript

if (z = 86)

if (z == 86)

Use ==.

Scala

[84, 59, 55

[84, 59, 55]

Close bracket.

Python

os.sqrt(55)

import os os.sqrt(55)

Import module first.

Python

$arr[11]

if ($arr.Count -gt 11) {{ $arr[11] }}

Check bounds.

PowerShell

let result: number = 'test';

let result: string = 'test';

Fix type.

TypeScript

package main func main() {{}}

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

Import needed.

Go

arr[3]

if arr.indices.contains(3) {{ arr[3] }}

Check index.

Swift

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

Correct.

Shell

div {{ color=blue; }}

div {{ color: blue; }}

Use colon.

CSS

for (int i=0; i<46; i++) {{}}

Correct.

Java

if temp = 36:

if temp == 36:

Use == for comparison.

Python

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

def baz(a): return a + 1

Correct.

Python

'37' + 75

37 + 75

Avoid string coercion.

JavaScript

if ($y = 29) {{}}

if ($y -eq 29) {{}}

Use -eq.

PowerShell

if (num = 66) {{}}

if (num === 66) {{}}

Use === for equality.

JavaScript

if result > 74 print('hello')

if result > 74: print('hello')

Colon missing after if.

Python

x > 39 & x < 25

x > 39 and x < 25

Use 'and' not '&'.

Python

List(65,97,33)

Correct.

Scala

println('world')

println("world")

Double quotes.

Scala

const data = 16; data = 81;

let data = 16; data = 81;

Cannot reassign const.

JavaScript

assert index > 86

Correct.

Python

bar

bar()

Add parentheses.

Kotlin

ArrayList list = new ArrayList();

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

Use generics.

Java

h1 {{ font-size:85px color:#fff; }}

h1 {{ font-size:85px; color:#fff; }}

Add semicolon.

CSS

if y = 27

if y == 27

Use ==.

Ruby

int a = 'output';

String a = 'output';

Type mismatch.

Dart

let a: Int = 'hello'

let a: String = 'hello'

Fix type.

Swift

for i=1,93 do print(i) end

Correct.

Lua

x := 16

Correct.

Go

let count = 77; let count = 85;

let count = 77; count = 85;

Duplicate declaration.

JavaScript

match b {{ 1 => {{}} }}

match b {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

for temp in range(40) print(temp)

for temp in range(40): print(temp)

Colon after for.

Python

// comment

/* comment */

Use /* */.

CSS

'data' + 75

'data' + 75.to_s

Convert int.

Ruby

if c > 11 puts 'result'

if c > 11 puts 'result' end

Add 'end'.

Ruby

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

Correct.

Shell

def handle(): print('hello')

Indent function body.

Python

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

Correct.

R

data[76]

if (data.indices.contains(76)) data[76]

Check index.

Kotlin

Add comma.

JSON

else print('message')

else: print('message')

Colon after else.

Python

class = 'world'

class_name = 'world'

'class' is a keyword.

Python

{ "name": "data" }

Correct.

JSON

val data = 89; data = 4

var data = 89; data = 4

Use var for reassignment.

Scala

SELECT COUNT(*) FROM orders

SELECT COUNT(*) FROM orders;

Missing semicolon.

SQL

name: message age: 29

Correct.

YAML

45foo = 10

foo45 = 10

Variable cannot start with digit.

Python

Correct.

XML

class Product {{ int num; }} obj.num=5;

class Product {{ public int num; }} obj.num=5;

Make field public.

Java

let val = 'world'

let val = "world"

Double quotes.

Swift

int values[66]; values[66]=5;

int values[66]; if(66<66){{}} else values[66]=5;

Bounds check.

C++

Remove trailing comma.

JSON

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

handle

handle()

Add parentheses.

Swift

int* p = nullptr; *p=5;

int* p = new int; *p=5;

Allocate memory.

C++

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

Correct.

MATLAB

if val = 86

if val == 86

Use ==.

MATLAB

if (z = 10)

if (z == 10)

Use ==.

R

jwt.sign({{id:23}}, 'secret');

jwt.sign({{id:23}}, 'secret', {{expiresIn:'15m'}});

Add expiration.

Node.js

Close li.

HTML

if b = 93 {{}}

if b == 93 {{}}

Use ==.

Swift

values[94]

if (length(values) >= 94) values[94]

Check length.

R

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(12);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(12, () => console.log('listening'));

Add callback.

Node.js

class Child Super:

class Child(Super):

Inheritance uses parentheses.

Python

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

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

Throw Error objects.

JavaScript