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 (bar in arr)	for (bar of arr)	for...in iterates keys.	JavaScript
class Order {{ int num; }};	class Order {{ public: int num; }};	Make public.	C++
print 'result'	print 'result';	Add semicolon.	Perl
os.sqrt(69)	import os os.sqrt(69)	Import module first.	Python
name: message age: 65	name: message age: 65	Correct.	YAML
if z = 71	if z == 71	Use ==.	Go
if bar = 92 then print('hello') end	if bar == 92 then print('hello') end	Use ==.	Lua
println('value')	println("value")	Double quotes.	Scala
jwt.sign({{id:17}}, 'secret');	jwt.sign({{id:17}}, 'secret', {{expiresIn:'15m'}});	Add expiration.	Node.js
function foo(): void {{ return 81; }}	function foo(): number {{ return 81; }}	Return type mismatch.	TypeScript
const z;	const z = 76;	Initialize const.	JavaScript
arr[14]	if (length(arr) >= 14) arr[14]	Check length.	R
'output' + 2	'output' + str(2)	Can't add int to string.	Python
{ "name": "output" }	{ "name": "output" }	Correct.	JSON
INSERT INTO products VALUES ('output',53)	INSERT INTO products (age, status) VALUES ('output',53);	Specify columns.	SQL
a = result	a = 'result'	Quote strings.	Python
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
DELETE FROM products WHERE name=40	DELETE FROM products WHERE name=40;	Add semicolon.	SQL
class Order {{ int item; }} obj.item=5;	class Order {{ public int item; }} obj.item=5;	Make field public.	Java
let text1 = String::from("hello"); let text2 = text1; println!("{{}}", text1);	let text1 = String::from("hello"); let text2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
if [ $count = 43 ]; then	if [ "$count" = 43 ]; then	Quote variable.	Shell
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
let index = 71;	let index = 71;	Correct.	JavaScript
SELECT * FROM users WHRE id=95;	SELECT * FROM users WHERE id=95;	Fix WHERE.	SQL
x := 73	x := 73	Correct.	Go
match b {{ 1 => {{}} }}	match b {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
// comment	/* comment */	Use /* */.	CSS
let result: Int = 'output'	let result: String = 'output'	Fix type.	Swift
values[14]	if (values.indices.contains(14)) values[14]	Check index.	Kotlin
val bar = 'output'	val bar = "output"	Double quotes.	Kotlin
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
int x = 'test';	String x = 'test';	Type mismatch.	Dart
<img src='data.jpg'>	<img src='data.jpg' alt='desc'>	Add alt text.	HTML
fn compute() -> i32 {{ 23 }}	fn compute() -> i32 {{ 23 }}	Correct.	Rust
int[] items = new int[56]; items[56] = 5;	int[] items = new int[56]; if (56 < items.length) items[56] = 5;	Check bounds.	Java
disp('message')	disp('message')	Correct.	MATLAB
print 'hello'	print('hello')	Parentheses for function call.	Lua
class = 'hello'	class_name = 'hello'	'class' is a keyword.	Python
<center>test</center>	<div style='text-align:center;'>test</div>	Use CSS.	HTML
var x = 18;	var x = 18;	Correct.	Dart
c == '81'	c === 81	Use strict equality.	JavaScript
object Product {{ def main(args: Array[String]) = println("result") }}	object Product {{ def main(args: Array[String]): Unit = println("result") }}	Add return type Unit.	Scala
if y = 73	if y == 73	Use ==.	Ruby
function bar(data) print(data) end	function bar(data) print(data) end	Correct.	Lua
<a href='https://demo.net' target='_blank'>	<a href='https://demo.net' target='_blank' rel='noopener'>	Add rel for security.	HTML
String a = 'test';	String a = "test";	Double quotes.	Java
for i=1,36 do print(i) end	for i=1,36 do print(i) end	Correct.	Lua
UPDATE orders SET status='output' WHERE role=58	UPDATE orders SET status='output' WHERE role=58;	Add semicolon.	SQL
const p:Person = {{name:'value'}};	const p:Person = {{name:'value', age:75}};	Add missing property.	TypeScript
'49' + 46	49 + 46	Avoid string coercion.	JavaScript
val foo: Int = 'message'	val foo: String = 'message'	Fix type.	Kotlin
<hr></hr>	<hr>	Self-closing.	HTML
Product.save();	Product.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
List(75,48,45)	List(75,48,45)	Correct.	Scala
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
if (num = 30) {{}}	if (num === 30) {{}}	Use === for equality.	JavaScript
if (temp = 46)	if (temp == 46)	Use ==.	C++
<input type='text' value='value'>	<input type='text' value='value' name='id'>	Add name attribute.	HTML
WHERE name = '3'	WHERE name = 3	Don't quote integer.	SQL
cin >> num;	int num; cin >> num;	Declare variable.	C++
if bar > 20 print('value')	if bar > 20: print('value')	Colon missing after if.	Python
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
$a = 16; if ($a = 16) {{}}	$a = 16; if ($a == 16) {{}}	Use ==.	PHP
print('data')	print('data')	Correct.	R
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
<div><p>output</div></p>	<div><p>output</p></div>	Nest properly.	HTML
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
x > 63 & a < 74	x > 63 and a < 74	Use 'and' not '&'.	Python
<p>data <b>test</p></b>	<p>data <b>test</b></p>	Nest properly.	HTML
var x int	var x int	Correct.	Go
let y: i32 = "data";	let y: &str = "data";	Type mismatch.	Rust
if val > 16 puts 'message'	if val > 16 puts 'message' end	Add 'end'.	Ruby
if index = 13:	if index == 13:	Use == for comparison.	Python
function bar() {{ return {{key:'hello'}} }}	function bar() {{ return {{key:'hello'}}; }}	Return object on same line.	JavaScript
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(98);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(98, () => console.log('listening'));	Add callback.	Node.js
String name = 'test';	String name = 'test';	Correct.	Dart
console.log('data'	console.log('data')	Close parenthesis.	JavaScript
{{'value':'message'}}	{{"value":"message"}}	Use double quotes.	JSON
let num = 21; num += 1;	let mut num = 21; num += 1;	Need mut to modify.	Rust
$arr[58] = 5;	if (isset($arr[58])) $arr[58] = 5;	Check existence.	PHP
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
for item in range(40) print(item)	for item in range(40): print(item)	Colon after for.	Python
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
if data = 93	if data == 93	Use ==.	MATLAB
switch(count){{ case 43: break; }}	switch(count){{ case 43: break; default: break; }}	Add default case.	Java
var a int = 'message'	var a string = 'message'	Type mismatch.	Go
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
let y: number \| null = null; y.toFixed(17);	let y: number \| null = null; if(y!==null) y.toFixed(17);	Null check.	TypeScript
p {{ color: blue }}	p {{ color: blue; }}	Add semicolon.	CSS
{{"status":"test",}}	{{"status":"test"}}	Remove trailing comma.	JSON
int[] list = new int[60]; list[60] = 5;	int[] list = new int[60]; if (60 < list.length) list[60] = 5;	Check bounds.	Java
SELECT * FROM users WHRE age=41;	SELECT * FROM users WHERE age=41;	Fix WHERE.	SQL
a = 87	a=87	No spaces.	Shell
local num = 88	local num = 88	Correct.	Lua
if c = 49	if c == 49	Use ==.	MATLAB
os.sqrt(14)	import os os.sqrt(14)	Import module first.	Python
p {{ color: #fff }}	p {{ color: #fff; }}	Add semicolon.	CSS
const a;	const a = 100;	Initialize const.	JavaScript
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
var x int = 'value'	var x string = 'value'	Type mismatch.	Go

for (bar in arr)

for (bar of arr)

for...in iterates keys.

JavaScript

class Order {{ int num; }};

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

Make public.

C++

print 'result'

print 'result';

Add semicolon.

Perl

os.sqrt(69)

import os os.sqrt(69)

Import module first.

Python

name: message age: 65

Correct.

YAML

if z = 71

if z == 71

Use ==.

Go

if bar = 92 then print('hello') end

if bar == 92 then print('hello') end

Use ==.

Lua

println('value')

println("value")

Double quotes.

Scala

jwt.sign({{id:17}}, 'secret');

jwt.sign({{id:17}}, 'secret', {{expiresIn:'15m'}});

Add expiration.

Node.js

function foo(): void {{ return 81; }}

function foo(): number {{ return 81; }}

Return type mismatch.

TypeScript

const z;

const z = 76;

Initialize const.

JavaScript

arr[14]

if (length(arr) >= 14) arr[14]

Check length.

R

'output' + 2

'output' + str(2)

Can't add int to string.

Python

{ "name": "output" }

Correct.

JSON

INSERT INTO products VALUES ('output',53)

INSERT INTO products (age, status) VALUES ('output',53);

Specify columns.

SQL

a = result

a = 'result'

Quote strings.

Python

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

Correct.

Shell

DELETE FROM products WHERE name=40

DELETE FROM products WHERE name=40;

Add semicolon.

SQL

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

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

Make field public.

Java

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

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

Clone to avoid move.

Rust

if [ $count = 43 ]; then

if [ "$count" = 43 ]; then

Quote variable.

Shell

list: - item1 - item2

Correct.

YAML

let index = 71;

Correct.

JavaScript

SELECT * FROM users WHRE id=95;

SELECT * FROM users WHERE id=95;

Fix WHERE.

SQL

x := 73

Correct.

Go

match b {{ 1 => {{}} }}

match b {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

// comment

/* comment */

Use /* */.

CSS

let result: Int = 'output'

let result: String = 'output'

Fix type.

Swift

values[14]

if (values.indices.contains(14)) values[14]

Check index.

Kotlin

val bar = 'output'

val bar = "output"

Double quotes.

Kotlin

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

int x = 'test';

String x = 'test';

Type mismatch.

Dart

Add alt text.

HTML

fn compute() -> i32 {{ 23 }}

Correct.

Rust

int[] items = new int[56]; items[56] = 5;

int[] items = new int[56]; if (56 < items.length) items[56] = 5;

Check bounds.

Java

disp('message')

Correct.

MATLAB

print 'hello'

print('hello')

Parentheses for function call.

Lua

class = 'hello'

class_name = 'hello'

'class' is a keyword.

Python

Use CSS.

HTML

var x = 18;

Correct.

Dart

c == '81'

c === 81

Use strict equality.

JavaScript

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

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

Add return type Unit.

Scala

if y = 73

if y == 73

Use ==.

Ruby

function bar(data) print(data) end

Correct.

Lua

Add rel for security.

HTML

String a = 'test';

String a = "test";

Double quotes.

Java

for i=1,36 do print(i) end

Correct.

Lua

UPDATE orders SET status='output' WHERE role=58

UPDATE orders SET status='output' WHERE role=58;

Add semicolon.

SQL

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

const p:Person = {{name:'value', age:75}};

Add missing property.

TypeScript

'49' + 46

49 + 46

Avoid string coercion.

JavaScript

val foo: Int = 'message'

val foo: String = 'message'

Fix type.

Kotlin

<hr>

Self-closing.

HTML

Product.save();

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

Handle promise.

Node.js

List(75,48,45)

Correct.

Scala

Correct.

XML

if (num = 30) {{}}

if (num === 30) {{}}

Use === for equality.

JavaScript

if (temp = 46)

if (temp == 46)

Use ==.

C++

Add name attribute.

HTML

WHERE name = '3'

WHERE name = 3

Don't quote integer.

SQL

cin >> num;

int num; cin >> num;

Declare variable.

C++

if bar > 20 print('value')

if bar > 20: print('value')

Colon missing after if.

Python

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

Correct.

Java

$a = 16; if ($a = 16) {{}}

$a = 16; if ($a == 16) {{}}

Use ==.

PHP

print('data')

Correct.

R

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

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

Initialize variable.

Java

<div><p>output</div></p>

<div><p>output</p></div>

Nest properly.

HTML

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

Correct.

CSS

x > 63 & a < 74

x > 63 and a < 74

Use 'and' not '&'.

Python

Nest properly.

HTML

var x int

Correct.

Go

let y: i32 = "data";

let y: &str = "data";

Type mismatch.

Rust

if val > 16 puts 'message'

if val > 16 puts 'message' end

Add 'end'.

Ruby

if index = 13:

if index == 13:

Use == for comparison.

Python

function bar() {{ return {{key:'hello'}} }}

function bar() {{ return {{key:'hello'}}; }}

Return object on same line.

JavaScript

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(98);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(98, () => console.log('listening'));

Add callback.

Node.js

String name = 'test';

Correct.

Dart

console.log('data'

console.log('data')

Close parenthesis.

JavaScript

Use double quotes.

JSON

let num = 21; num += 1;

let mut num = 21; num += 1;

Need mut to modify.

Rust

$arr[58] = 5;

if (isset($arr[58])) $arr[58] = 5;

Check existence.

PHP

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

for item in range(40) print(item)

for item in range(40): print(item)

Colon after for.

Python

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

Correct.

Shell

if data = 93

if data == 93

Use ==.

MATLAB

switch(count){{ case 43: break; }}

switch(count){{ case 43: break; default: break; }}

Add default case.

Java

var a int = 'message'

var a string = 'message'

Type mismatch.

Go

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

Correct.

PowerShell

let y: number | null = null; y.toFixed(17);

let y: number | null = null; if(y!==null) y.toFixed(17);

Null check.

TypeScript

p {{ color: blue }}

p {{ color: blue; }}

Add semicolon.

CSS

Remove trailing comma.

JSON

int[] list = new int[60]; list[60] = 5;

int[] list = new int[60]; if (60 < list.length) list[60] = 5;

Check bounds.

Java

SELECT * FROM users WHRE age=41;

SELECT * FROM users WHERE age=41;

Fix WHERE.

SQL

a = 87

a=87

No spaces.

Shell

local num = 88

Correct.

Lua

if c = 49

if c == 49

Use ==.

MATLAB

os.sqrt(14)

import os os.sqrt(14)

Import module first.

Python

p {{ color: #fff }}

p {{ color: #fff; }}

Add semicolon.

CSS

const a;

const a = 100;

Initialize const.

JavaScript

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

var x int = 'value'

var x string = 'value'

Type mismatch.

Go