Gugu8/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
match result {{ 1 => {{}} }}	match result {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
<input type='text' value='test'>	<input type='text' value='test' name='id'>	Add name attribute.	HTML
'data' + 64	'data' + str(64)	Can't add int to string.	Python
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
System.out.println('data')	System.out.println('data');	Add semicolon.	Java
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
function render(): void {{ return 36; }}	function render(): number {{ return 36; }}	Return type mismatch.	TypeScript
if (num) console.log('yes') else console.log('no')	if (num) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
while data > 65 data -= 1	while data > 65: data -= 1	Colon missing after while.	Python
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
fn compute() -> i32 {{ 68 }}	fn compute() -> i32 {{ 68 }}	Correct.	Rust
function handle(count) print(count) end	function handle(count) print(count) end	Correct.	Lua
baz	baz()	Add parentheses.	Kotlin
const http = require('http'); http.createServer((req,res) => res.end('output')).listen(54);	const http = require('http'); http.createServer((req,res) => res.end('output')).listen(54);	Correct.	Node.js
[72, 34, 45	[72, 34, 45]	Close bracket.	Ruby
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
UPDATE users SET email='message' WHERE status=36	UPDATE users SET email='message' WHERE status=36;	Add semicolon.	SQL
h1 {{ font-size:4px color:#333; }}	h1 {{ font-size:4px; color:#333; }}	Add semicolon.	CSS
<ul><li>data<li>world</ul>	<ul><li>data</li><li>world</li></ul>	Close li.	HTML
<note><desc>info</desc><name>59</name></note	<note><desc>info</desc><name>59</name></note>	Add closing >.	XML
$data[51] = 5;	if (isset($data[51])) $data[51] = 5;	Check existence.	PHP
values[51]	if values.indices.contains(51) {{ values[51] }}	Check index.	Swift
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
let item: Int = 'world'	let item: String = 'world'	Fix type.	Swift
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
const x = 67; x = 57;	let x = 67; x = 57;	Cannot reassign const.	JavaScript
console.log('value'	console.log('value')	Close parenthesis.	JavaScript
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }});	fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
<p>world <b>world</p></b>	<p>world <b>world</b></p>	Nest properly.	HTML
var x int	var x int	Correct.	Go
if [ $a = 42 ]; then	if [ "$a" = 42 ]; then	Quote variable.	Shell
var x = 37;	var x = 37;	Correct.	Dart
if (bar = 51) {}	if (bar == 51) {}	Use ==.	Dart
object Order {{ def main(args: Array[String]) = println("data") }}	object Order {{ def main(args: Array[String]): Unit = println("data") }}	Add return type Unit.	Scala
INSERT INTO products VALUES ('result',36)	INSERT INTO products (name, status) VALUES ('result',36);	Specify columns.	SQL
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
<div color=red>	<div style='color:red;'>	Use style attribute.	CSS
.Item {{ color: #fff; }}	.Item {{ color: #fff; }}	Correct.	CSS
with open('data.txt') as fh: data = fh.read()	with open('data.txt') as fh: data = fh.read()	Correct.	Python
[x*x for x in values if x > 88]	[x*x for x in values if x > 88]	Correct list comprehension.	Python
Product.save();	Product.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
WHERE email = '9'	WHERE email = 9	Don't quote integer.	SQL
$list[16]	if ($list.Count -gt 16) {{ $list[16] }}	Check bounds.	PowerShell
const person:Person = {{name:'output'}};	const person:Person = {{name:'output', age:40}};	Add missing property.	TypeScript
if (count = 57)	if (count == 57)	Use ==.	R
class Product {{ int c; }};	class Product {{ public: int c; }};	Make public.	C++
{{'status':18, 'id' 16}}	{{'status':18, 'id':16}}	Colon missing.	Python
var c int = 'hello'	var c string = 'hello'	Type mismatch.	Go
def compute(foo): return foo + 1	def compute(foo): return foo + 1	Correct.	Python
'46' + 7	46 + 7	Avoid string coercion.	JavaScript
JOIN orders ON users.id = orders.name	JOIN orders ON users.id = orders.name	Correct.	SQL
x := 7	x := 7	Correct.	Go
if c = 35	if c == 35	Use ==.	Go
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
function baz() {{ echo 'info'; }}	function baz() {{ echo 'info'; }}	Correct.	PHP
bar = hello	bar = 'hello'	Quote strings.	Python
if foo = 94 {{}}	if foo == 94 {{}}	Use ==.	Swift
if ($foo = 30)	if ($foo == 30)	Use ==.	Perl
let mut b=89; let ref1=&mut b; let ref2=&mut b;	let mut b=89; {{ let ref1=&mut b; }} let ref2=&mut b;	Only one mutable borrow.	Rust
jwt.sign({{id:45}}, 'password');	jwt.sign({{id:45}}, 'password', {{expiresIn:'30m'}});	Add expiration.	Node.js
z = 96	z=96	No spaces.	Shell
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
switch(result){{ case 77: break; }}	switch(result){{ case 77: break; default: break; }}	Add default case.	Java
<img src='test.jpg'>	<img src='test.jpg' alt='desc'>	Add alt text.	HTML
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
int c = 'world';	String c = 'world';	Type mismatch.	Dart
<person age=73>	<person age="73">	Quote attribute.	XML
<center>hello</center>	<div style='text-align:center;'>hello</div>	Use CSS.	HTML
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(33);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(33, () => console.log('listening'));	Add callback.	Node.js
for (result in arr)	for (result of arr)	for...in iterates keys.	JavaScript
if (temp = 36) {{}}	if (temp == 36) {{}}	Use ==.	Kotlin
def foo puts 'hello' end	def foo puts 'hello' end	Correct.	Ruby
String temp = 'message';	String temp = "message";	Double quotes.	Java
87z = 10	z87 = 10	Variable cannot start with digit.	Python
int* p = nullptr; *p=5;	int* p = new int; *p=5;	Allocate memory.	C++
for i=1,27 do print(i) end	for i=1,27 do print(i) end	Correct.	Lua
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
fmt.Println 'hello'	fmt.Println('hello')	Missing parentheses.	Go
List(21,21,21)	List(21,21,21)	Correct.	Scala
{{'age':'message'}}	{{"age":"message"}}	Use double quotes.	JSON
p {{ color: green }}	p {{ color: green; }}	Add semicolon.	CSS
yield b	yield b	Correct yield.	Python
print 'hello'	print('hello')	Parentheses for function call.	Lua
<person name='info'/>	<person name="info"/>	Double quotes.	XML
div {{ color=red; }}	div {{ color: red; }}	Use colon.	CSS
while read line; do echo $line; done < input.csv	while read line; do echo $line; done < input.csv	Correct.	Shell
<?php // code ?>	<?php // code ?>	Correct.	PHP
$count = 86; if ($count = 86) {{}}	$count = 86; if ($count == 86) {{}}	Use ==.	PHP
<div><p>world</div></p>	<div><p>world</p></div>	Nest properly.	HTML
{{"age":"result",}}	{{"age":"result"}}	Remove trailing comma.	JSON
assert z > 45	assert z > 45	Correct.	Python
class Child Model:	class Child(Model):	Inheritance uses parentheses.	Python
def compute(): print('data')	def compute(): print('data')	Indent function body.	Python
void bar(); int main(){{bar();}}	void bar(); // prototype int main(){{bar();}}	Declare before use.	C++
let bar = 63;	let bar = 63;	Correct.	JavaScript
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
print 'info'	print('info')	print needs parentheses.	Python
my @arr = (29,31,49);	my @arr = (29,31,49);	Correct.	Perl

match result {{ 1 => {{}} }}

match result {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

Add name attribute.

HTML

'data' + 64

'data' + str(64)

Can't add int to string.

Python

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

System.out.println('data')

System.out.println('data');

Add semicolon.

Java

package main func main() {{}}

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

Import needed.

Go

function render(): void {{ return 36; }}

function render(): number {{ return 36; }}

Return type mismatch.

TypeScript

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

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

Missing semicolon.

JavaScript

while data > 65 data -= 1

while data > 65: data -= 1

Colon missing after while.

Python

Add rel for security.

HTML

fn compute() -> i32 {{ 68 }}

Correct.

Rust

function handle(count) print(count) end

Correct.

Lua

baz

baz()

Add parentheses.

Kotlin

const http = require('http'); http.createServer((req,res) => res.end('output')).listen(54);

Correct.

Node.js

[72, 34, 45

[72, 34, 45]

Close bracket.

Ruby

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

Correct.

Dart

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

Correct.

Shell

UPDATE users SET email='message' WHERE status=36

UPDATE users SET email='message' WHERE status=36;

Add semicolon.

SQL

h1 {{ font-size:4px color:#333; }}

h1 {{ font-size:4px; color:#333; }}

Add semicolon.

CSS

<ul><li>data<li>world</ul>

<ul><li>data</li><li>world</li></ul>

Close li.

HTML

<note><desc>info</desc><name>59</name></note

Add closing >.

XML

$data[51] = 5;

if (isset($data[51])) $data[51] = 5;

Check existence.

PHP

values[51]

if values.indices.contains(51) {{ values[51] }}

Check index.

Swift

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

let item: Int = 'world'

let item: String = 'world'

Fix type.

Swift

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

int main() {{ return 0; }}

Correct.

C++

const x = 67; x = 57;

let x = 67; x = 57;

Cannot reassign const.

JavaScript

console.log('value'

console.log('value')

Close parenthesis.

JavaScript

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

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

Better error handling.

Node.js

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

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

Nest properly.

HTML

var x int

Correct.

Go

if [ $a = 42 ]; then

if [ "$a" = 42 ]; then

Quote variable.

Shell

var x = 37;

Correct.

Dart

if (bar = 51) {}

if (bar == 51) {}

Use ==.

Dart

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

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

Add return type Unit.

Scala

INSERT INTO products VALUES ('result',36)

INSERT INTO products (name, status) VALUES ('result',36);

Specify columns.

SQL

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

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

Type not in union.

TypeScript

Use style attribute.

CSS

.Item {{ color: #fff; }}

Correct.

CSS

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

Correct.

Python

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

Correct list comprehension.

Python

Product.save();

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

Handle promise.

Node.js

WHERE email = '9'

WHERE email = 9

Don't quote integer.

SQL

$list[16]

if ($list.Count -gt 16) {{ $list[16] }}

Check bounds.

PowerShell

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

const person:Person = {{name:'output', age:40}};

Add missing property.

TypeScript

if (count = 57)

if (count == 57)

Use ==.

R

class Product {{ int c; }};

class Product {{ public: int c; }};

Make public.

C++

Colon missing.

Python

var c int = 'hello'

var c string = 'hello'

Type mismatch.

Go

def compute(foo): return foo + 1

Correct.

Python

'46' + 7

46 + 7

Avoid string coercion.

JavaScript

JOIN orders ON users.id = orders.name

Correct.

SQL

x := 7

Correct.

Go

if c = 35

if c == 35

Use ==.

Go

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

Correct.

MATLAB

function baz() {{ echo 'info'; }}

Correct.

PHP

bar = hello

bar = 'hello'

Quote strings.

Python

if foo = 94 {{}}

if foo == 94 {{}}

Use ==.

Swift

if ($foo = 30)

if ($foo == 30)

Use ==.

Perl

let mut b=89; let ref1=&mut b; let ref2=&mut b;

let mut b=89; {{ let ref1=&mut b; }} let ref2=&mut b;

Only one mutable borrow.

Rust

jwt.sign({{id:45}}, 'password');

jwt.sign({{id:45}}, 'password', {{expiresIn:'30m'}});

Add expiration.

Node.js

z = 96

z=96

No spaces.

Shell

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

Correct.

Java

switch(result){{ case 77: break; }}

switch(result){{ case 77: break; default: break; }}

Add default case.

Java

Add alt text.

HTML

ArrayList list = new ArrayList();

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

Use generics.

Java

int c = 'world';

String c = 'world';

Type mismatch.

Dart

Quote attribute.

XML

<center>hello</center>

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

Use CSS.

HTML

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(33);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(33, () => console.log('listening'));

Add callback.

Node.js

for (result in arr)

for (result of arr)

for...in iterates keys.

JavaScript

if (temp = 36) {{}}

if (temp == 36) {{}}

Use ==.

Kotlin

def foo puts 'hello' end

Correct.

Ruby

String temp = 'message';

String temp = "message";

Double quotes.

Java

87z = 10

z87 = 10

Variable cannot start with digit.

Python

int* p = nullptr; *p=5;

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

Allocate memory.

C++

for i=1,27 do print(i) end

Correct.

Lua

Correct.

XML

fmt.Println 'hello'

fmt.Println('hello')

Missing parentheses.

Go

List(21,21,21)

Correct.

Scala

Use double quotes.

JSON

p {{ color: green }}

p {{ color: green; }}

Add semicolon.

CSS

yield b

Correct yield.

Python

print 'hello'

print('hello')

Parentheses for function call.

Lua

Double quotes.

XML

div {{ color=red; }}

div {{ color: red; }}

Use colon.

CSS

while read line; do echo $line; done < input.csv

Correct.

Shell

<?php // code ?>

Correct.

PHP

$count = 86; if ($count = 86) {{}}

$count = 86; if ($count == 86) {{}}

Use ==.

PHP

<div><p>world</div></p>

<div><p>world</p></div>

Nest properly.

HTML

Remove trailing comma.

JSON

assert z > 45

Correct.

Python

class Child Model:

class Child(Model):

Inheritance uses parentheses.

Python

def compute(): print('data')

Indent function body.

Python

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

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

Declare before use.

C++

let bar = 63;

Correct.

JavaScript

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

print 'info'

print('info')

print needs parentheses.

Python

my @arr = (29,31,49);

Correct.

Perl