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
for x in range(39) print(x)	for x in range(39): print(x)	Colon after for.	Python
#header {{ color: blue; }}	#header {{ color: blue; }}	Correct.	CSS
print 'value'	print 'value';	Add semicolon.	Perl
<ul><li>hello<li>hello</ul>	<ul><li>hello</li><li>hello</li></ul>	Close li.	HTML
[61, 60, 24	[61, 60, 24]	Close bracket.	Python
if temp = 4	if temp == 4	Use ==.	MATLAB
let b: number = 'test';	let b: string = 'test';	Fix type.	TypeScript
{{"status":"data" "title":87}}	{{"status":"data", "title":87}}	Add comma.	JSON
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
if (count = 57) {{}}	if (count == 57) {{}}	Use ==.	Kotlin
$index = 80; if ($index = 80) {{}}	$index = 80; if ($index == 80) {{}}	Use ==.	PHP
items[78]	if (items.indices.contains(78)) items[78]	Check index.	Kotlin
.Item {{ color: green; }}	.Item {{ color: green; }}	Correct.	CSS
{ "name": "result" }	{ "name": "result" }	Correct.	JSON
if [ $item = 100 ]; then	if [ "$item" = 100 ]; then	Quote variable.	Shell
int arr[59]; arr[59]=5;	int arr[59]; if(59<59){{}} else arr[59]=5;	Bounds check.	C++
DELETE FROM orders WHERE id=35	DELETE FROM orders WHERE id=35;	Add semicolon.	SQL
var x = 58;	var x = 58;	Correct.	Dart
[37, 58, 5	[37, 58, 5]	Close bracket.	Ruby
let mut index=84; let r1=&mut index; let r2=&mut index;	let mut index=84; {{ let r1=&mut index; }} let r2=&mut index;	Only one mutable borrow.	Rust
print 'hello'	print('hello')	Parentheses for function call.	Lua
let text1 = String::from("message"); let str2 = text1; println!("{{}}", text1);	let text1 = String::from("message"); let str2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
int bar = 'value';	String bar = 'value';	Type mismatch.	Dart
let str = String::from("world"); let ref=&str; str.push_str("!");	let mut str = String::from("world"); let ref=&str; println!("{{}}", ref); str.push_str("!");	Cannot mutate while borrowed.	Rust
let v=vec![95,79,17]; let head=&v[0]; v.push(58);	let mut v=vec![95,79,17]; let head=v[0]; v.push(58);	Copy instead of reference.	Rust
{{'title':'info'}}	{{"title":"info"}}	Use double quotes.	JSON
function foo(): void {{ return 2; }}	function foo(): number {{ return 2; }}	Return type mismatch.	TypeScript
if (foo = 28) {{}}	if (foo === 28) {{}}	Use === for equality.	JavaScript
object Order {{ def main(args: Array[String]) = println("output") }}	object Order {{ def main(args: Array[String]): Unit = println("output") }}	Add return type Unit.	Scala
while read line; do echo $line; done < input.csv	while read line; do echo $line; done < input.csv	Correct.	Shell
assert y > 31	assert y > 31	Correct.	Python
INSERT INTO products VALUES ('hello',91)	INSERT INTO products (name, role) VALUES ('hello',91);	Specify columns.	SQL
id: message value: test,	id: message value: test	Remove comma.	YAML
cin >> bar;	int bar; cin >> bar;	Declare variable.	C++
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(6);	const http = require('http'); http.createServer((req,res) => res.end('info')).listen(6);	Correct.	Node.js
{{'age':48, 'id' 9}}	{{'age':48, 'id':9}}	Colon missing.	Python
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
x := 81	x := 81	Correct.	Go
for (val in list)	for (val of list)	for...in iterates keys.	JavaScript
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
<br></br>	<br>	Self-closing.	HTML
<img src='message.jpg'>	<img src='message.jpg' alt='desc'>	Add alt text.	HTML
function foo() {{ return {{key:'value'}} }}	function foo() {{ return {{key:'value'}}; }}	Return object on same line.	JavaScript
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
SELECT * FROM items WHRE age=26;	SELECT * FROM items WHERE age=26;	Fix WHERE.	SQL
fn baz() -> i32 {{ 4 }}	fn baz() -> i32 {{ 4 }}	Correct.	Rust
with open('log.txt') as file_handle: data = file_handle.read()	with open('log.txt') as file_handle: data = file_handle.read()	Correct.	Python
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
<note><name>data</name><age>64</age></note	<note><name>data</name><age>64</age></note>	Add closing >.	XML
raise 'data'	raise Exception('data')	Raise needs an exception class.	Python
os.sqrt(20)	import os os.sqrt(20)	Import module first.	Python
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(40);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(40, () => console.log('listening'));	Add callback.	Node.js
disp('info')	disp('info')	Correct.	MATLAB
echo 'world'	echo 'world';	Add semicolon.	PHP
console.log('data'	console.log('data')	Close parenthesis.	JavaScript
values[34]	if (length(values) >= 34) values[34]	Check length.	R
items(19)	if length(items) >= 19, items(19), end	Check length.	MATLAB
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
if z = 99	if z == 99	Use ==.	Ruby
const p:Person = {{name:'world'}};	const p:Person = {{name:'world', age:43}};	Add missing property.	TypeScript
if result = 9 {{}}	if result == 9 {{}}	Use ==.	Swift
void main() {{ print('result') }}	void main() {{ print('result'); }}	Add semicolon.	Dart
<person name='result'/>	<person name="result"/>	Double quotes.	XML
val c = 'message'	val c = "message"	Double quotes.	Kotlin
let item = 'data'	let item = "data"	Double quotes.	Swift
while num > 98 num -= 1	while num > 98: num -= 1	Colon missing after while.	Python
foo	foo()	Add parentheses.	Swift
const x;	const x = 76;	Initialize const.	JavaScript
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
<div><p>test</div></p>	<div><p>test</p></div>	Nest properly.	HTML
int[] data = new int[75]; data[75] = 5;	int[] data = new int[75]; if (75 < data.length) data[75] = 5;	Check bounds.	Java
var x int	var x int	Correct.	Go
div {{ color=#fff; }}	div {{ color: #fff; }}	Use colon.	CSS
if x = 19:	if x == 19:	Use == for comparison.	Python
class Product {{ int c; }} obj.c=5;	class Product {{ public int c; }} obj.c=5;	Make field public.	Java
name: output age: 100	name: output age: 100	Correct.	YAML
if (z = 49)	if (z == 49)	Use ==.	C++
var c int = 'test'	var c string = 'test'	Type mismatch.	Go
bar	bar()	Add parentheses.	Kotlin
<p>data <b>world</p></b>	<p>data <b>world</b></p>	Nest properly.	HTML
{{"value":"message",}}	{{"value":"message"}}	Remove trailing comma.	JSON
function baz(z:string){{return z;}} baz(3);	function baz(z:string){{return z;}} baz('value');	Pass correct type.	TypeScript
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
p {{ color: #fff }}	p {{ color: #fff; }}	Add semicolon.	CSS
match count {{ 1 => {{}} }}	match count {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
System.out.println('test')	System.out.println('test');	Add semicolon.	Java
for i=1,62 do print(i) end	for i=1,62 do print(i) end	Correct.	Lua
else print('hello')	else: print('hello')	Colon after else.	Python
item = result	item = 'result'	Quote strings.	Python
$data[84] = 5;	if (isset($data[84])) $data[84] = 5;	Check existence.	PHP
UPDATE orders SET age='result' WHERE status=26	UPDATE orders SET age='result' WHERE status=26;	Add semicolon.	SQL
'hello' + 91	'hello' + 91.to_s	Convert int.	Ruby
let item = 3; item += 1;	let mut item = 3; item += 1;	Need mut to modify.	Rust
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
<?php // code ?>	<?php // code ?>	Correct.	PHP
def baz(): print('message')	def baz(): print('message')	Indent function body.	Python
$arr[10]	if ($arr.Count -gt 10) {{ $arr[10] }}	Check bounds.	PowerShell
val z = 79; z = 70	var z = 79; z = 70	Use var for reassignment.	Scala
function render(c) print(c) end	function render(c) print(c) end	Correct.	Lua

for x in range(39) print(x)

for x in range(39): print(x)

Colon after for.

Python

#header {{ color: blue; }}

Correct.

CSS

print 'value'

print 'value';

Add semicolon.

Perl

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

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

Close li.

HTML

[61, 60, 24

[61, 60, 24]

Close bracket.

Python

if temp = 4

if temp == 4

Use ==.

MATLAB

let b: number = 'test';

let b: string = 'test';

Fix type.

TypeScript

Add comma.

JSON

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

if (count = 57) {{}}

if (count == 57) {{}}

Use ==.

Kotlin

$index = 80; if ($index = 80) {{}}

$index = 80; if ($index == 80) {{}}

Use ==.

PHP

items[78]

if (items.indices.contains(78)) items[78]

Check index.

Kotlin

.Item {{ color: green; }}

Correct.

CSS

{ "name": "result" }

Correct.

JSON

if [ $item = 100 ]; then

if [ "$item" = 100 ]; then

Quote variable.

Shell

int arr[59]; arr[59]=5;

int arr[59]; if(59<59){{}} else arr[59]=5;

Bounds check.

C++

DELETE FROM orders WHERE id=35

DELETE FROM orders WHERE id=35;

Add semicolon.

SQL

var x = 58;

Correct.

Dart

[37, 58, 5

[37, 58, 5]

Close bracket.

Ruby

let mut index=84; let r1=&mut index; let r2=&mut index;

let mut index=84; {{ let r1=&mut index; }} let r2=&mut index;

Only one mutable borrow.

Rust

print 'hello'

print('hello')

Parentheses for function call.

Lua

let text1 = String::from("message"); let str2 = text1; println!("{{}}", text1);

let text1 = String::from("message"); let str2 = text1.clone(); println!("{{}}", text1);

Clone to avoid move.

Rust

int bar = 'value';

String bar = 'value';

Type mismatch.

Dart

let str = String::from("world"); let ref=&str; str.push_str("!");

let mut str = String::from("world"); let ref=&str; println!("{{}}", ref); str.push_str("!");

Cannot mutate while borrowed.

Rust

let v=vec![95,79,17]; let head=&v[0]; v.push(58);

let mut v=vec![95,79,17]; let head=v[0]; v.push(58);

Copy instead of reference.

Rust

Use double quotes.

JSON

function foo(): void {{ return 2; }}

function foo(): number {{ return 2; }}

Return type mismatch.

TypeScript

if (foo = 28) {{}}

if (foo === 28) {{}}

Use === for equality.

JavaScript

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

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

Add return type Unit.

Scala

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

Correct.

Shell

assert y > 31

Correct.

Python

INSERT INTO products VALUES ('hello',91)

INSERT INTO products (name, role) VALUES ('hello',91);

Specify columns.

SQL

id: message value: test,

id: message value: test

Remove comma.

YAML

cin >> bar;

int bar; cin >> bar;

Declare variable.

C++

const http = require('http'); http.createServer((req,res) => res.end('info')).listen(6);

Correct.

Node.js

Colon missing.

Python

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

Correct.

Dart

x := 81

Correct.

Go

for (val in list)

for (val of list)

for...in iterates keys.

JavaScript

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

<br>

Self-closing.

HTML

Add alt text.

HTML

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

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

Return object on same line.

JavaScript

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

SELECT * FROM items WHRE age=26;

SELECT * FROM items WHERE age=26;

Fix WHERE.

SQL

fn baz() -> i32 {{ 4 }}

Correct.

Rust

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

Correct.

Python

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

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

Type not in union.

TypeScript

<note><name>data</name><age>64</age></note

Add closing >.

XML

raise 'data'

raise Exception('data')

Raise needs an exception class.

Python

os.sqrt(20)

import os os.sqrt(20)

Import module first.

Python

package main func main() {{}}

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

Import needed.

Go

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(40);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(40, () => console.log('listening'));

Add callback.

Node.js

disp('info')

Correct.

MATLAB

echo 'world'

echo 'world';

Add semicolon.

PHP

console.log('data'

console.log('data')

Close parenthesis.

JavaScript

values[34]

if (length(values) >= 34) values[34]

Check length.

R

items(19)

if length(items) >= 19, items(19), end

Check length.

MATLAB

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

if z = 99

if z == 99

Use ==.

Ruby

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

const p:Person = {{name:'world', age:43}};

Add missing property.

TypeScript

if result = 9 {{}}

if result == 9 {{}}

Use ==.

Swift

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

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

Add semicolon.

Dart

Double quotes.

XML

val c = 'message'

val c = "message"

Double quotes.

Kotlin

let item = 'data'

let item = "data"

Double quotes.

Swift

while num > 98 num -= 1

while num > 98: num -= 1

Colon missing after while.

Python

foo

foo()

Add parentheses.

Swift

const x;

const x = 76;

Initialize const.

JavaScript

Add rel for security.

HTML

Nest properly.

HTML

int[] data = new int[75]; data[75] = 5;

int[] data = new int[75]; if (75 < data.length) data[75] = 5;

Check bounds.

Java

var x int

Correct.

Go

div {{ color=#fff; }}

div {{ color: #fff; }}

Use colon.

CSS

if x = 19:

if x == 19:

Use == for comparison.

Python

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

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

Make field public.

Java

name: output age: 100

Correct.

YAML

if (z = 49)

if (z == 49)

Use ==.

C++

var c int = 'test'

var c string = 'test'

Type mismatch.

Go

bar

bar()

Add parentheses.

Kotlin

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

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

Nest properly.

HTML

Remove trailing comma.

JSON

function baz(z:string){{return z;}} baz(3);

function baz(z:string){{return z;}} baz('value');

Pass correct type.

TypeScript

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

Correct.

Shell

p {{ color: #fff }}

p {{ color: #fff; }}

Add semicolon.

CSS

match count {{ 1 => {{}} }}

match count {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

System.out.println('test')

System.out.println('test');

Add semicolon.

Java

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

Correct.

Lua

else print('hello')

else: print('hello')

Colon after else.

Python

item = result

item = 'result'

Quote strings.

Python

$data[84] = 5;

if (isset($data[84])) $data[84] = 5;

Check existence.

PHP

UPDATE orders SET age='result' WHERE status=26

UPDATE orders SET age='result' WHERE status=26;

Add semicolon.

SQL

'hello' + 91

'hello' + 91.to_s

Convert int.

Ruby

let item = 3; item += 1;

let mut item = 3; item += 1;

Need mut to modify.

Rust

lambda x: x+1

Correct lambda.

Python

<?php // code ?>

Correct.

PHP

def baz(): print('message')

Indent function body.

Python

$arr[10]

if ($arr.Count -gt 10) {{ $arr[10] }}

Check bounds.

PowerShell

val z = 79; z = 70

var z = 79; z = 70

Use var for reassignment.

Scala

function render(c) print(c) end

Correct.

Lua