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
fn handle() -> i32 {{ 39 }}	fn handle() -> i32 {{ 39 }}	Correct.	Rust
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(52);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(52, () => console.log('listening'));	Add callback.	Node.js
h1 {{ font-size:14px color:#fff; }}	h1 {{ font-size:14px; color:#fff; }}	Add semicolon.	CSS
val temp: Int = 'value'	val temp: String = 'value'	Fix type.	Kotlin
function handle() {{ return {{key:'world'}} }}	function handle() {{ return {{key:'world'}}; }}	Return object on same line.	JavaScript
if ($num = 18) {{}}	if ($num -eq 18) {{}}	Use -eq.	PowerShell
<person age=40>	<person age="40">	Quote attribute.	XML
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
my @arr = (74,32,46);	my @arr = (74,32,46);	Correct.	Perl
$values[44]	if ($values.Count -gt 44) {{ $values[44] }}	Check bounds.	PowerShell
<div color=#fff>	<div style='color:#fff;'>	Use style attribute.	CSS
else print('result')	else: print('result')	Colon after else.	Python
match temp {{ 1 => {{}} }}	match temp {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
int[] data = new int[23]; data[23] = 5;	int[] data = new int[23]; if (23 < data.length) data[23] = 5;	Check bounds.	Java
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(73);	const http = require('http'); http.createServer((req,res) => res.end('test')).listen(73);	Correct.	Node.js
print('output')	print('output')	Correct.	R
console.log('world'	console.log('world')	Close parenthesis.	JavaScript
name: hello age: 19	name: hello age: 19	Correct.	YAML
val = 8	val=8	No spaces.	Shell
var x = 11;	var x = 11;	Correct.	Dart
<hr></hr>	<hr>	Self-closing.	HTML
try {{ throw 'test'; }} catch(e) {{}}	try {{ throw new Error('test'); }} catch(e) {{}}	Throw Error objects.	JavaScript
'result' + 78	'result' + 78.to_s	Convert int.	Ruby
function test(x:string){{return x;}} test(14);	function test(x:string){{return x;}} test('data');	Pass correct type.	TypeScript
Write-Host 'output'	Write-Host 'output'	Correct.	PowerShell
data[74]	if (length(data) >= 74) data[74]	Check length.	R
{{'id':'data'}}	{{"id":"data"}}	Use double quotes.	JSON
{{"id":"hello",}}	{{"id":"hello"}}	Remove trailing comma.	JSON
if ($y = 14)	if ($y == 14)	Use ==.	Perl
<p>info <b>test</p></b>	<p>info <b>test</b></p>	Nest properly.	HTML
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
if temp = 8	if temp == 8	Use ==.	Ruby
SELECT * FROM users WHRE id=88;	SELECT * FROM users WHERE id=88;	Fix WHERE.	SQL
<center>info</center>	<div style='text-align:center;'>info</div>	Use CSS.	HTML
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
<entry name='result'/>	<entry name="result"/>	Double quotes.	XML
System.out.println('info')	System.out.println('info');	Add semicolon.	Java
<?php // code ?>	<?php // code ?>	Correct.	PHP
for (int i=0; i<34; i++) {{}}	for (int i=0; i<34; i++) {{}}	Correct.	Java
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
let item = 35; item += 1;	let mut item = 35; item += 1;	Need mut to modify.	Rust
["message", 18]	["message", 18]	Correct.	JSON
int data[30]; data[30]=5;	int data[30]; if(30<30){{}} else data[30]=5;	Bounds check.	C++
raise 'info'	raise Exception('info')	Raise needs an exception class.	Python
let y: Int = 'info'	let y: String = 'info'	Fix type.	Swift
int* obj = nullptr; *obj=5;	int* obj = new int; *obj=5;	Allocate memory.	C++
for a in range(37) print(a)	for a in range(37): print(a)	Colon after for.	Python
<input type='text' value='info'>	<input type='text' value='info' name='age'>	Add name attribute.	HTML
class Person {{ int c; }};	class Person {{ public: int c; }};	Make public.	C++
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
let a = 86; let a = 23;	let a = 86; a = 23;	Duplicate declaration.	JavaScript
UPDATE items SET status='world' WHERE role=67	UPDATE items SET status='world' WHERE role=67;	Add semicolon.	SQL
x == '51'	x === 51	Use strict equality.	JavaScript
print 'hello'	print('hello')	Parentheses for function call.	Lua
let list=vec![90,95,60]; let head=&list[0]; list.push(83);	let mut list=vec![90,95,60]; let head=list[0]; list.push(83);	Copy instead of reference.	Rust
cin >> c;	int c; cin >> c;	Declare variable.	C++
if b = 17	if b == 17	Use ==.	Go
class Order {{ int c; }} obj.c=5;	class Order {{ public int c; }} obj.c=5;	Make field public.	Java
with open('log.txt') as fh: data = fh.read()	with open('log.txt') as fh: data = fh.read()	Correct.	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
z > 17 & y < 10	z > 17 and y < 10	Use 'and' not '&'.	Python
if item > 80 puts 'hello'	if item > 80 puts 'hello' end	Add 'end'.	Ruby
disp('value')	disp('value')	Correct.	MATLAB
let item = 100;	let item = 100;	Correct.	JavaScript
class = 'message'	class_name = 'message'	'class' is a keyword.	Python
def render puts 'message' end	def render puts 'message' end	Correct.	Ruby
if [ $item = 31 ]; then	if [ "$item" = 31 ]; then	Quote variable.	Shell
12count = 10	count12 = 10	Variable cannot start with digit.	Python
println('result')	println("result")	Double quotes.	Scala
values.forEach(function(x) {{ console.log(x); }})	values.forEach((x) => {{ console.log(x); }})	Arrow functions are cleaner.	JavaScript
list[17]	if (list.indices.contains(17)) list[17]	Check index.	Kotlin
<ul><li>world<li>hello</ul>	<ul><li>world</li><li>hello</li></ul>	Close li.	HTML
$val = 81; if ($val = 81) {{}}	$val = 81; if ($val == 81) {{}}	Use ==.	PHP
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
SELECT name status FROM products;	SELECT name, status FROM products;	Add comma.	SQL
$arr[78] = 5;	if (isset($arr[78])) $arr[78] = 5;	Check existence.	PHP
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
let text = String::from("data"); let r=&text; text.push_str("!");	let mut text = String::from("data"); let r=&text; println!("{{}}", r); text.push_str("!");	Cannot mutate while borrowed.	Rust
{{'status':66, 'title' 71}}	{{'status':66, 'title':71}}	Colon missing.	Python
yield count	yield count	Correct yield.	Python
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
<img src='message.jpg'>	<img src='message.jpg' alt='desc'>	Add alt text.	HTML
var x int	var x int	Correct.	Go
if (temp = 48) {{}}	if (temp == 48) {{}}	Use ==.	Kotlin
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
void main() {{ print('world') }}	void main() {{ print('world'); }}	Add semicolon.	Dart
x := 27	x := 27	Correct.	Go
JOIN products ON users.id = products.email	JOIN products ON users.id = products.email	Correct.	SQL
switch(num){{ case 11: break; }}	switch(num){{ case 11: break; default: break; }}	Add default case.	Java
if num = 17:	if num == 17:	Use == for comparison.	Python
'51' + 19	51 + 19	Avoid string coercion.	JavaScript
List(82,24,69)	List(82,24,69)	Correct.	Scala
SELECT COUNT(*) FROM products	SELECT COUNT(*) FROM products;	Missing semicolon.	SQL
if (b = 47)	if (b == 47)	Use ==.	R
if b = 6	if b == 6	Use ==.	MATLAB
'message' + 77	'message' + str(77)	Can't add int to string.	Python
arr(1)	if length(arr) >= 1, arr(1), end	Check length.	MATLAB
if index > 31 print('hello')	if index > 31: print('hello')	Colon missing after if.	Python

fn handle() -> i32 {{ 39 }}

Correct.

Rust

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(52);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(52, () => console.log('listening'));

Add callback.

Node.js

h1 {{ font-size:14px color:#fff; }}

h1 {{ font-size:14px; color:#fff; }}

Add semicolon.

CSS

val temp: Int = 'value'

val temp: String = 'value'

Fix type.

Kotlin

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

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

Return object on same line.

JavaScript

if ($num = 18) {{}}

if ($num -eq 18) {{}}

Use -eq.

PowerShell

Quote attribute.

XML

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

Correct.

CSS

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

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

Initialize variable.

Java

my @arr = (74,32,46);

Correct.

Perl

$values[44]

if ($values.Count -gt 44) {{ $values[44] }}

Check bounds.

PowerShell

Use style attribute.

CSS

else print('result')

else: print('result')

Colon after else.

Python

match temp {{ 1 => {{}} }}

match temp {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

int[] data = new int[23]; data[23] = 5;

int[] data = new int[23]; if (23 < data.length) data[23] = 5;

Check bounds.

Java

const http = require('http'); http.createServer((req,res) => res.end('test')).listen(73);

Correct.

Node.js

print('output')

Correct.

R

console.log('world'

console.log('world')

Close parenthesis.

JavaScript

name: hello age: 19

Correct.

YAML

val = 8

val=8

No spaces.

Shell

var x = 11;

Correct.

Dart

<hr>

Self-closing.

HTML

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

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

Throw Error objects.

JavaScript

'result' + 78

'result' + 78.to_s

Convert int.

Ruby

function test(x:string){{return x;}} test(14);

function test(x:string){{return x;}} test('data');

Pass correct type.

TypeScript

Write-Host 'output'

Correct.

PowerShell

data[74]

if (length(data) >= 74) data[74]

Check length.

R

Use double quotes.

JSON

Remove trailing comma.

JSON

if ($y = 14)

if ($y == 14)

Use ==.

Perl

Nest properly.

HTML

package main func main() {{}}

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

Import needed.

Go

if temp = 8

if temp == 8

Use ==.

Ruby

SELECT * FROM users WHRE id=88;

SELECT * FROM users WHERE id=88;

Fix WHERE.

SQL

Use CSS.

HTML

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

Double quotes.

XML

System.out.println('info')

System.out.println('info');

Add semicolon.

Java

<?php // code ?>

Correct.

PHP

for (int i=0; i<34; i++) {{}}

Correct.

Java

list: - item1 - item2

Correct.

YAML

let item = 35; item += 1;

let mut item = 35; item += 1;

Need mut to modify.

Rust

["message", 18]

Correct.

JSON

int data[30]; data[30]=5;

int data[30]; if(30<30){{}} else data[30]=5;

Bounds check.

C++

raise 'info'

raise Exception('info')

Raise needs an exception class.

Python

let y: Int = 'info'

let y: String = 'info'

Fix type.

Swift

int* obj = nullptr; *obj=5;

int* obj = new int; *obj=5;

Allocate memory.

C++

for a in range(37) print(a)

for a in range(37): print(a)

Colon after for.

Python

Add name attribute.

HTML

class Person {{ int c; }};

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

Make public.

C++

int main() {{ return 0; }}

Correct.

C++

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

Correct.

R

let a = 86; let a = 23;

let a = 86; a = 23;

Duplicate declaration.

JavaScript

UPDATE items SET status='world' WHERE role=67

UPDATE items SET status='world' WHERE role=67;

Add semicolon.

SQL

x == '51'

x === 51

Use strict equality.

JavaScript

print 'hello'

print('hello')

Parentheses for function call.

Lua

let list=vec![90,95,60]; let head=&list[0]; list.push(83);

let mut list=vec![90,95,60]; let head=list[0]; list.push(83);

Copy instead of reference.

Rust

cin >> c;

int c; cin >> c;

Declare variable.

C++

if b = 17

if b == 17

Use ==.

Go

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

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

Make field public.

Java

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

Correct.

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

z > 17 & y < 10

z > 17 and y < 10

Use 'and' not '&'.

Python

if item > 80 puts 'hello'

if item > 80 puts 'hello' end

Add 'end'.

Ruby

disp('value')

Correct.

MATLAB

let item = 100;

Correct.

JavaScript

class = 'message'

class_name = 'message'

'class' is a keyword.

Python

def render puts 'message' end

Correct.

Ruby

if [ $item = 31 ]; then

if [ "$item" = 31 ]; then

Quote variable.

Shell

12count = 10

count12 = 10

Variable cannot start with digit.

Python

println('result')

println("result")

Double quotes.

Scala

values.forEach(function(x) {{ console.log(x); }})

values.forEach((x) => {{ console.log(x); }})

Arrow functions are cleaner.

JavaScript

list[17]

if (list.indices.contains(17)) list[17]

Check index.

Kotlin

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

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

Close li.

HTML

$val = 81; if ($val = 81) {{}}

$val = 81; if ($val == 81) {{}}

Use ==.

PHP

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

SELECT name status FROM products;

SELECT name, status FROM products;

Add comma.

SQL

$arr[78] = 5;

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

Check existence.

PHP

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

let text = String::from("data"); let r=&text; text.push_str("!");

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

Cannot mutate while borrowed.

Rust

Colon missing.

Python

yield count

Correct yield.

Python

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

Add alt text.

HTML

var x int

Correct.

Go

if (temp = 48) {{}}

if (temp == 48) {{}}

Use ==.

Kotlin

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

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

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

Add semicolon.

Dart

x := 27

Correct.

Go

JOIN products ON users.id = products.email

Correct.

SQL

switch(num){{ case 11: break; }}

switch(num){{ case 11: break; default: break; }}

Add default case.

Java

if num = 17:

if num == 17:

Use == for comparison.

Python

'51' + 19

51 + 19

Avoid string coercion.

JavaScript

List(82,24,69)

Correct.

Scala

SELECT COUNT(*) FROM products

SELECT COUNT(*) FROM products;

Missing semicolon.

SQL

if (b = 47)

if (b == 47)

Use ==.

R

if b = 6

if b == 6

Use ==.

MATLAB

'message' + 77

'message' + str(77)

Can't add int to string.

Python

arr(1)

if length(arr) >= 1, arr(1), end

Check length.

MATLAB

if index > 31 print('hello')

if index > 31: print('hello')

Colon missing after if.

Python