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
'5' + 8	5 + 8	Avoid string coercion.	JavaScript
echo world world	echo 'world world'	Quote to prevent splitting.	Shell
console.log('info'	console.log('info')	Close parenthesis.	JavaScript
let data = 'hello'	let data = "hello"	Double quotes.	Swift
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
if (data = 51) {}	if (data == 51) {}	Use ==.	Dart
<entry><name>result</name><age>65</age></entry	<entry><name>result</name><age>65</age></entry>	Add closing >.	XML
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
while read line; do echo $line; done < config.json	while read line; do echo $line; done < config.json	Correct.	Shell
DELETE FROM users WHERE email=38	DELETE FROM users WHERE email=38;	Add semicolon.	SQL
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
<person name='test'/>	<person name="test"/>	Double quotes.	XML
'data' + 18	'data' + 18.to_s	Convert int.	Ruby
Write-Host 'hello'	Write-Host 'hello'	Correct.	PowerShell
let count = 56;	let count = 56;	Correct.	JavaScript
echo 'hello'	echo 'hello';	Add semicolon.	PHP
<div><p>data</div></p>	<div><p>data</p></div>	Nest properly.	HTML
function foo(): void {{ return 87; }}	function foo(): number {{ return 87; }}	Return type mismatch.	TypeScript
if (val = 96)	if (val == 96)	Use ==.	R
void foo(); int main(){{foo();}}	void foo(); // prototype int main(){{foo();}}	Declare before use.	C++
class Person {{ int b; }};	class Person {{ public: int b; }};	Make public.	C++
let x: i32 = "test";	let x: &str = "test";	Type mismatch.	Rust
print('value')	print('value')	Correct.	R
var x = 65;	var x = 65;	Correct.	Dart
const z = 8; z = 46;	let z = 8; z = 46;	Cannot reassign const.	JavaScript
assert result > 85	assert result > 85	Correct.	Python
let text1 = String::from("result"); let text2 = text1; println!("{{}}", text1);	let text1 = String::from("result"); let text2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
for index in range(77) print(index)	for index in range(77): print(index)	Colon after for.	Python
let b: number \| null = null; b.toFixed(47);	let b: number \| null = null; if(b!==null) b.toFixed(47);	Null check.	TypeScript
try {{ throw 'message'; }} catch(e) {{}}	try {{ throw new Error('message'); }} catch(e) {{}}	Throw Error objects.	JavaScript
while index > 81 index -= 1	while index > 81: index -= 1	Colon missing after while.	Python
index = data	index = 'data'	Quote strings.	Python
List(13,15,93)	List(13,15,93)	Correct.	Scala
System.out.println('value')	System.out.println('value');	Add semicolon.	Java
<ul><li>test<li>hello</ul>	<ul><li>test</li><li>hello</li></ul>	Close li.	HTML
$val = 46; if ($val = 46) {{}}	$val = 46; if ($val == 46) {{}}	Use ==.	PHP
Order.save();	Order.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
bar = 42	bar=42	No spaces.	Shell
yield x	yield x	Correct yield.	Python
String item = 'world';	String item = "world";	Double quotes.	Java
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
p {{ color: blue }}	p {{ color: blue; }}	Add semicolon.	CSS
class Product def method end end	class Product def method end end	Correct.	Ruby
if (z = 28)	if (z == 28)	Use ==.	C++
["data", 59]	["data", 59]	Correct.	JSON
else print('message')	else: print('message')	Colon after else.	Python
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
div {{ color=red; }}	div {{ color: red; }}	Use colon.	CSS
if c = 7	if c == 7	Use ==.	MATLAB
const person:Person = {{name:'world'}};	const person:Person = {{name:'world', age:59}};	Add missing property.	TypeScript
if (temp) console.log('yes') else console.log('no')	if (temp) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
[x*x for x in arr if x > 24]	[x*x for x in arr if x > 24]	Correct list comprehension.	Python
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
if ($num = 6)	if ($num == 6)	Use ==.	Perl
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
<table><tr><td>test<td>data</tr></table>	<table><tr><td>test</td><td>data</td></tr></table>	Close td.	HTML
function test(count:string){{return count;}} test(57);	function test(count:string){{return count;}} test('value');	Pass correct type.	TypeScript
my @arr = (89,21,73);	my @arr = (89,21,73);	Correct.	Perl
function render(a) print(a) end	function render(a) print(a) end	Correct.	Lua
echo info hello	echo 'info hello'	Quote to prevent splitting.	Shell
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
for (int i=0; i<68; i++) {{}}	for (int i=0; i<68; i++) {{}}	Correct.	Java
INSERT INTO items VALUES ('result',75)	INSERT INTO items (age, status) VALUES ('result',75);	Specify columns.	SQL
handle	handle()	Add parentheses.	Kotlin
{{'name':'result'}}	{{"name":"result"}}	Use double quotes.	JSON
function process() {{ return {{key:'world'}} }}	function process() {{ return {{key:'world'}}; }}	Return object on same line.	JavaScript
if ($foo = 81) {{}}	if ($foo -eq 81) {{}}	Use -eq.	PowerShell
if foo > 94 print('result')	if foo > 94: print('result')	Colon missing after if.	Python
function foo() {{ echo 'value'; }}	function foo() {{ echo 'value'; }}	Correct.	PHP
print 'test'	print('test')	print needs parentheses.	Python
[100, 34, 43	[100, 34, 43]	Close bracket.	Python
{{"age":"value" "value":13}}	{{"age":"value", "value":13}}	Add comma.	JSON
{{'age':33, 'name' 99}}	{{'age':33, 'name':99}}	Colon missing.	Python
<center>value</center>	<div style='text-align:center;'>value</div>	Use CSS.	HTML
<hr></hr>	<hr>	Self-closing.	HTML
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
{{"title":"info",}}	{{"title":"info"}}	Remove trailing comma.	JSON
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
{ "name": "hello" }	{ "name": "hello" }	Correct.	JSON
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }});	fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
UPDATE items SET name='info' WHERE role=37	UPDATE items SET name='info' WHERE role=37;	Add semicolon.	SQL
name: data age: 76	name: data age: 76	Correct.	YAML
if (result = 55) {{}}	if (result == 55) {{}}	Use ==.	Kotlin
'23' + 25	23 + 25	Avoid string coercion.	JavaScript
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
def handle puts 'hello' end	def handle puts 'hello' end	Correct.	Ruby
list[20]	if (list.indices.contains(20)) list[20]	Check index.	Kotlin
class Item {{ int temp; }} obj.temp=5;	class Item {{ public int temp; }} obj.temp=5;	Make field public.	Java
37index = 10	index37 = 10	Variable cannot start with digit.	Python
jwt.sign({{id:30}}, 'token');	jwt.sign({{id:30}}, 'token', {{expiresIn:'2h'}});	Add expiration.	Node.js
if foo = 32	if foo == 32	Use ==.	Go
if (b = 58)	if (b == 58)	Use ==.	Scala
raise 'world'	raise Exception('world')	Raise needs an exception class.	Python
JOIN profiles ON products.id = profiles.status	JOIN profiles ON products.id = profiles.status	Correct.	SQL
x := 13	x := 13	Correct.	Go
def render(): print('data')	def render(): print('data')	Indent function body.	Python
match c {{ 1 => {{}} }}	match c {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
val z = 24; z = 24	var z = 24; z = 24	Use var for reassignment.	Scala

'5' + 8

5 + 8

Avoid string coercion.

JavaScript

echo world world

echo 'world world'

Quote to prevent splitting.

Shell

console.log('info'

console.log('info')

Close parenthesis.

JavaScript

let data = 'hello'

let data = "hello"

Double quotes.

Swift

Add rel for security.

HTML

if (data = 51) {}

if (data == 51) {}

Use ==.

Dart

<entry><name>result</name><age>65</age></entry

<entry><name>result</name><age>65</age></entry>

Add closing >.

XML

Correct.

XML

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

Correct.

Shell

DELETE FROM users WHERE email=38

DELETE FROM users WHERE email=38;

Add semicolon.

SQL

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

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

Correct.

PowerShell

Double quotes.

XML

'data' + 18

'data' + 18.to_s

Convert int.

Ruby

Write-Host 'hello'

Correct.

PowerShell

let count = 56;

Correct.

JavaScript

echo 'hello'

echo 'hello';

Add semicolon.

PHP

Nest properly.

HTML

function foo(): void {{ return 87; }}

function foo(): number {{ return 87; }}

Return type mismatch.

TypeScript

if (val = 96)

if (val == 96)

Use ==.

R

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

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

Declare before use.

C++

class Person {{ int b; }};

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

Make public.

C++

let x: i32 = "test";

let x: &str = "test";

Type mismatch.

Rust

print('value')

Correct.

R

var x = 65;

Correct.

Dart

const z = 8; z = 46;

let z = 8; z = 46;

Cannot reassign const.

JavaScript

assert result > 85

Correct.

Python

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

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

Clone to avoid move.

Rust

for index in range(77) print(index)

for index in range(77): print(index)

Colon after for.

Python

let b: number | null = null; b.toFixed(47);

let b: number | null = null; if(b!==null) b.toFixed(47);

Null check.

TypeScript

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

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

Throw Error objects.

JavaScript

while index > 81 index -= 1

while index > 81: index -= 1

Colon missing after while.

Python

index = data

index = 'data'

Quote strings.

Python

List(13,15,93)

Correct.

Scala

System.out.println('value')

System.out.println('value');

Add semicolon.

Java

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

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

Close li.

HTML

$val = 46; if ($val = 46) {{}}

$val = 46; if ($val == 46) {{}}

Use ==.

PHP

Order.save();

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

Handle promise.

Node.js

bar = 42

bar=42

No spaces.

Shell

yield x

Correct yield.

Python

String item = 'world';

String item = "world";

Double quotes.

Java

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

Correct.

Java

p {{ color: blue }}

p {{ color: blue; }}

Add semicolon.

CSS

class Product def method end end

Correct.

Ruby

if (z = 28)

if (z == 28)

Use ==.

C++

["data", 59]

Correct.

JSON

else print('message')

else: print('message')

Colon after else.

Python

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

Correct.

MATLAB

div {{ color=red; }}

div {{ color: red; }}

Use colon.

CSS

if c = 7

if c == 7

Use ==.

MATLAB

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

const person:Person = {{name:'world', age:59}};

Add missing property.

TypeScript

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

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

Missing semicolon.

JavaScript

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

Correct list comprehension.

Python

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

Correct.

CSS

if ($num = 6)

if ($num == 6)

Use ==.

Perl

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

package main func main() {{}}

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

Import needed.

Go

Close td.

HTML

function test(count:string){{return count;}} test(57);

function test(count:string){{return count;}} test('value');

Pass correct type.

TypeScript

my @arr = (89,21,73);

Correct.

Perl

function render(a) print(a) end

Correct.

Lua

echo info hello

echo 'info hello'

Quote to prevent splitting.

Shell

list: - item1 - item2

Correct.

YAML

for (int i=0; i<68; i++) {{}}

Correct.

Java

INSERT INTO items VALUES ('result',75)

INSERT INTO items (age, status) VALUES ('result',75);

Specify columns.

SQL

handle

handle()

Add parentheses.

Kotlin

Use double quotes.

JSON

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

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

Return object on same line.

JavaScript

if ($foo = 81) {{}}

if ($foo -eq 81) {{}}

Use -eq.

PowerShell

if foo > 94 print('result')

if foo > 94: print('result')

Colon missing after if.

Python

function foo() {{ echo 'value'; }}

Correct.

PHP

print 'test'

print('test')

print needs parentheses.

Python

[100, 34, 43

[100, 34, 43]

Close bracket.

Python

Add comma.

JSON

Colon missing.

Python

<center>value</center>

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

Use CSS.

HTML

<hr>

Self-closing.

HTML

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

Correct.

Shell

Remove trailing comma.

JSON

lambda x: x+1

Correct lambda.

Python

{ "name": "hello" }

Correct.

JSON

fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }});

fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});

Better error handling.

Node.js

UPDATE items SET name='info' WHERE role=37

UPDATE items SET name='info' WHERE role=37;

Add semicolon.

SQL

name: data age: 76

Correct.

YAML

if (result = 55) {{}}

if (result == 55) {{}}

Use ==.

Kotlin

'23' + 25

23 + 25

Avoid string coercion.

JavaScript

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

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

Type not in union.

TypeScript

def handle puts 'hello' end

Correct.

Ruby

list[20]

if (list.indices.contains(20)) list[20]

Check index.

Kotlin

class Item {{ int temp; }} obj.temp=5;

class Item {{ public int temp; }} obj.temp=5;

Make field public.

Java

37index = 10

index37 = 10

Variable cannot start with digit.

Python

jwt.sign({{id:30}}, 'token');

jwt.sign({{id:30}}, 'token', {{expiresIn:'2h'}});

Add expiration.

Node.js

if foo = 32

if foo == 32

Use ==.

Go

if (b = 58)

if (b == 58)

Use ==.

Scala

raise 'world'

raise Exception('world')

Raise needs an exception class.

Python

JOIN profiles ON products.id = profiles.status

Correct.

SQL

x := 13

Correct.

Go

def render(): print('data')

Indent function body.

Python

match c {{ 1 => {{}} }}

match c {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

val z = 24; z = 24

var z = 24; z = 24

Use var for reassignment.

Scala