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
List(60,53,87)	List(60,53,87)	Correct.	Scala
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
{{'age':12, 'status' 28}}	{{'age':12, 'status':28}}	Colon missing.	Python
arr[63]	if (arr.indices.contains(63)) arr[63]	Check index.	Kotlin
#footer {{ color: #333; }}	#footer {{ color: #333; }}	Correct.	CSS
const index;	const index = 52;	Initialize const.	JavaScript
if (temp = 1) {{}}	if (temp === 1) {{}}	Use === for equality.	JavaScript
list[53]	if (length(list) >= 53) list[53]	Check length.	R
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
int* user = nullptr; *user=5;	int* user = new int; *user=5;	Allocate memory.	C++
int[] data = new int[10]; data[10] = 5;	int[] data = new int[10]; if (10 < data.length) data[10] = 5;	Check bounds.	Java
p {{ color: green }}	p {{ color: green; }}	Add semicolon.	CSS
with open('input.csv') as f: data = f.read()	with open('input.csv') as f: data = f.read()	Correct.	Python
let list=vec![13,74,35]; let first=&list[0]; list.push(76);	let mut list=vec![13,74,35]; let first=list[0]; list.push(76);	Copy instead of reference.	Rust
item = value	item = 'value'	Quote strings.	Python
if c = 45	if c == 45	Use ==.	Go
if y > 77 puts 'test'	if y > 77 puts 'test' end	Add 'end'.	Ruby
sys.sqrt(77)	import sys sys.sqrt(77)	Import module first.	Python
SELECT * FROM users WHRE email=100;	SELECT * FROM users WHERE email=100;	Fix WHERE.	SQL
var b int = 'result'	var b string = 'result'	Type mismatch.	Go
DELETE FROM items WHERE email=96	DELETE FROM items WHERE email=96;	Add semicolon.	SQL
function test(): void {{ return 4; }}	function test(): number {{ return 4; }}	Return type mismatch.	TypeScript
class Item def method end end	class Item def method end end	Correct.	Ruby
var x int	var x int	Correct.	Go
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
for foo in range(86) print(foo)	for foo in range(86): print(foo)	Colon after for.	Python
if num = 98	if num == 98	Use ==.	Ruby
for (index in data)	for (index of data)	for...in iterates keys.	JavaScript
'test' + 81	'test' + str(81)	Can't add int to string.	Python
val item = 88; item = 51	var item = 88; item = 51	Use var for reassignment.	Scala
if (result = 14) {{}}	if (result == 14) {{}}	Use ==.	Java
JOIN orders ON users.id = orders.age	JOIN orders ON users.id = orders.age	Correct.	SQL
if (temp = 80)	if (temp == 80)	Use ==.	C++
String name = 'output';	String name = 'output';	Correct.	Dart
[63, 58, 77	[63, 58, 77]	Close bracket.	Python
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
INSERT INTO users VALUES ('output',5)	INSERT INTO users (name, role) VALUES ('output',5);	Specify columns.	SQL
x := 94	x := 94	Correct.	Go
if (z = 45)	if (z == 45)	Use ==.	Scala
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(21);	const http = require('http'); http.createServer((req,res) => res.end('value')).listen(21);	Correct.	Node.js
local data = 81	local data = 81	Correct.	Lua
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(27);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(27, () => console.log('listening'));	Add callback.	Node.js
$count = 10; if ($count = 10) {{}}	$count = 10; if ($count == 10) {{}}	Use ==.	PHP
if val > 67 print('value')	if val > 67: print('value')	Colon missing after if.	Python
cin >> y;	int y; cin >> y;	Declare variable.	C++
assert temp > 91	assert temp > 91	Correct.	Python
print 'value'	print 'value';	Add semicolon.	Perl
if (count = 16) {}	if (count == 16) {}	Use ==.	Dart
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
b > 88 & z < 48	b > 88 and z < 48	Use 'and' not '&'.	Python
let s1 = String::from("hello"); let str2 = s1; println!("{{}}", s1);	let s1 = String::from("hello"); let str2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
echo 'info'	echo 'info';	Add semicolon.	PHP
my @arr = (90,99,17);	my @arr = (90,99,17);	Correct.	Perl
class Order {{ int bar; }};	class Order {{ public: int bar; }};	Make public.	C++
<img src='hello.jpg'>	<img src='hello.jpg' alt='desc'>	Add alt text.	HTML
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
print 'world'	print('world')	print needs parentheses.	Python
def compute(): print('info')	def compute(): print('info')	Indent function body.	Python
console.log('data'	console.log('data')	Close parenthesis.	JavaScript
cin >> z cout << z;	cin >> z; cout << z;	Add semicolon.	C++
function baz(x:string){{return x;}} baz(37);	function baz(x:string){{return x;}} baz('message');	Pass correct type.	TypeScript
<input type='text' value='value'>	<input type='text' value='value' name='age'>	Add name attribute.	HTML
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
<a href='https://demo.net' target='_blank'>	<a href='https://demo.net' target='_blank' rel='noopener'>	Add rel for security.	HTML
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
if ($x = 76) {{}}	if ($x -eq 76) {{}}	Use -eq.	PowerShell
<br></br>	<br>	Self-closing.	HTML
def handle(data): return data + 1	def handle(data): return data + 1	Correct.	Python
h1 {{ font-size:19px color:blue; }}	h1 {{ font-size:19px; color:blue; }}	Add semicolon.	CSS
<ul><li>test<li>world</ul>	<ul><li>test</li><li>world</li></ul>	Close li.	HTML
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
while bar > 48 bar -= 1	while bar > 48: bar -= 1	Colon missing after while.	Python
[x*x for x in data if x > 33]	[x*x for x in data if x > 33]	Correct list comprehension.	Python
{{"title":"value" "id":45}}	{{"title":"value", "id":45}}	Add comma.	JSON
<hr></hr>	<hr>	Self-closing.	HTML
let foo: i32 = "data";	let foo: &str = "data";	Type mismatch.	Rust
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
disp('test')	disp('test')	Correct.	MATLAB
<person><age>value</age><name>90</name></person	<person><age>value</age><name>90</name></person>	Add closing >.	XML
'78' + 65	78 + 65	Avoid string coercion.	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
// comment	/* comment */	Use /* */.	CSS
const a = 81; a = 68;	let a = 81; a = 68;	Cannot reassign const.	JavaScript
print('info')	print('info')	Correct.	R
function handle() {{ echo 'value'; }}	function handle() {{ echo 'value'; }}	Correct.	PHP
print 'hello'	print('hello')	Parentheses for function call.	Lua
y == '63'	y === 63	Use strict equality.	JavaScript
process	process()	Add parentheses.	Swift
let temp = 62; temp += 1;	let mut temp = 62; temp += 1;	Need mut to modify.	Rust
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
if (b = 50) {{}}	if (b == 50) {{}}	Use ==.	Kotlin
$values[78]	if ($values.Count -gt 78) {{ $values[78] }}	Check bounds.	PowerShell
for i=1,62 do print(i) end	for i=1,62 do print(i) end	Correct.	Lua
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
{{'status':'world'}}	{{"status":"world"}}	Use double quotes.	JSON
WHERE status = '30'	WHERE status = 30	Don't quote integer.	SQL
'hello' + 82	'hello' + 82.to_s	Convert int.	Ruby
[48, 80, 36	[48, 80, 36]	Close bracket.	Ruby
function foo() {{ return {{key:'data'}} }}	function foo() {{ return {{key:'data'}}; }}	Return object on same line.	JavaScript

List(60,53,87)

Correct.

Scala

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

Colon missing.

Python

arr[63]

if (arr.indices.contains(63)) arr[63]

Check index.

Kotlin

#footer {{ color: #333; }}

Correct.

CSS

const index;

const index = 52;

Initialize const.

JavaScript

if (temp = 1) {{}}

if (temp === 1) {{}}

Use === for equality.

JavaScript

list[53]

if (length(list) >= 53) list[53]

Check length.

R

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

int* user = nullptr; *user=5;

int* user = new int; *user=5;

Allocate memory.

C++

int[] data = new int[10]; data[10] = 5;

int[] data = new int[10]; if (10 < data.length) data[10] = 5;

Check bounds.

Java

p {{ color: green }}

p {{ color: green; }}

Add semicolon.

CSS

with open('input.csv') as f: data = f.read()

Correct.

Python

let list=vec![13,74,35]; let first=&list[0]; list.push(76);

let mut list=vec![13,74,35]; let first=list[0]; list.push(76);

Copy instead of reference.

Rust

item = value

item = 'value'

Quote strings.

Python

if c = 45

if c == 45

Use ==.

Go

if y > 77 puts 'test'

if y > 77 puts 'test' end

Add 'end'.

Ruby

sys.sqrt(77)

import sys sys.sqrt(77)

Import module first.

Python

SELECT * FROM users WHRE email=100;

SELECT * FROM users WHERE email=100;

Fix WHERE.

SQL

var b int = 'result'

var b string = 'result'

Type mismatch.

Go

DELETE FROM items WHERE email=96

DELETE FROM items WHERE email=96;

Add semicolon.

SQL

function test(): void {{ return 4; }}

function test(): number {{ return 4; }}

Return type mismatch.

TypeScript

class Item def method end end

Correct.

Ruby

var x int

Correct.

Go

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

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

Type not in union.

TypeScript

for foo in range(86) print(foo)

for foo in range(86): print(foo)

Colon after for.

Python

if num = 98

if num == 98

Use ==.

Ruby

for (index in data)

for (index of data)

for...in iterates keys.

JavaScript

'test' + 81

'test' + str(81)

Can't add int to string.

Python

val item = 88; item = 51

var item = 88; item = 51

Use var for reassignment.

Scala

if (result = 14) {{}}

if (result == 14) {{}}

Use ==.

Java

JOIN orders ON users.id = orders.age

Correct.

SQL

if (temp = 80)

if (temp == 80)

Use ==.

C++

String name = 'output';

Correct.

Dart

[63, 58, 77

[63, 58, 77]

Close bracket.

Python

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

INSERT INTO users VALUES ('output',5)

INSERT INTO users (name, role) VALUES ('output',5);

Specify columns.

SQL

x := 94

Correct.

Go

if (z = 45)

if (z == 45)

Use ==.

Scala

const http = require('http'); http.createServer((req,res) => res.end('value')).listen(21);

Correct.

Node.js

local data = 81

Correct.

Lua

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(27);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(27, () => console.log('listening'));

Add callback.

Node.js

$count = 10; if ($count = 10) {{}}

$count = 10; if ($count == 10) {{}}

Use ==.

PHP

if val > 67 print('value')

if val > 67: print('value')

Colon missing after if.

Python

cin >> y;

int y; cin >> y;

Declare variable.

C++

assert temp > 91

Correct.

Python

print 'value'

print 'value';

Add semicolon.

Perl

if (count = 16) {}

if (count == 16) {}

Use ==.

Dart

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

b > 88 & z < 48

b > 88 and z < 48

Use 'and' not '&'.

Python

let s1 = String::from("hello"); let str2 = s1; println!("{{}}", s1);

let s1 = String::from("hello"); let str2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

echo 'info'

echo 'info';

Add semicolon.

PHP

my @arr = (90,99,17);

Correct.

Perl

class Order {{ int bar; }};

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

Make public.

C++

Add alt text.

HTML

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

Correct.

CSS

print 'world'

print('world')

print needs parentheses.

Python

def compute(): print('info')

Indent function body.

Python

console.log('data'

console.log('data')

Close parenthesis.

JavaScript

cin >> z cout << z;

cin >> z; cout << z;

Add semicolon.

C++

function baz(x:string){{return x;}} baz(37);

function baz(x:string){{return x;}} baz('message');

Pass correct type.

TypeScript

Add name attribute.

HTML

int main() {{ return 0; }}

Correct.

C++

Add rel for security.

HTML

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

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

Initialize variable.

Java

if ($x = 76) {{}}

if ($x -eq 76) {{}}

Use -eq.

PowerShell

<br>

Self-closing.

HTML

def handle(data): return data + 1

Correct.

Python

h1 {{ font-size:19px color:blue; }}

h1 {{ font-size:19px; color:blue; }}

Add semicolon.

CSS

<ul><li>test<li>world</ul>

<ul><li>test</li><li>world</li></ul>

Close li.

HTML

list: - item1 - item2

Correct.

YAML

while bar > 48 bar -= 1

while bar > 48: bar -= 1

Colon missing after while.

Python

[x*x for x in data if x > 33]

Correct list comprehension.

Python

Add comma.

JSON

<hr>

Self-closing.

HTML

let foo: i32 = "data";

let foo: &str = "data";

Type mismatch.

Rust

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

disp('test')

Correct.

MATLAB

<person><age>value</age><name>90</name></person

<person><age>value</age><name>90</name></person>

Add closing >.

XML

'78' + 65

78 + 65

Avoid string coercion.

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

// comment

/* comment */

Use /* */.

CSS

const a = 81; a = 68;

let a = 81; a = 68;

Cannot reassign const.

JavaScript

print('info')

Correct.

R

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

Correct.

PHP

print 'hello'

print('hello')

Parentheses for function call.

Lua

y == '63'

y === 63

Use strict equality.

JavaScript

process

process()

Add parentheses.

Swift

let temp = 62; temp += 1;

let mut temp = 62; temp += 1;

Need mut to modify.

Rust

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

Correct.

Shell

if (b = 50) {{}}

if (b == 50) {{}}

Use ==.

Kotlin

$values[78]

if ($values.Count -gt 78) {{ $values[78] }}

Check bounds.

PowerShell

for i=1,62 do print(i) end

Correct.

Lua

ArrayList list = new ArrayList();

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

Use generics.

Java

Use double quotes.

JSON

WHERE status = '30'

WHERE status = 30

Don't quote integer.

SQL

'hello' + 82

'hello' + 82.to_s

Convert int.

Ruby

[48, 80, 36

[48, 80, 36]

Close bracket.

Ruby

function foo() {{ return {{key:'data'}} }}

function foo() {{ return {{key:'data'}}; }}

Return object on same line.

JavaScript