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
function compute(bar:string){{return bar;}} compute(75);	function compute(bar:string){{return bar;}} compute('data');	Pass correct type.	TypeScript
print 'hello'	print('hello')	Parentheses for function call.	Lua
var b int = 'info'	var b string = 'info'	Type mismatch.	Go
const temp;	const temp = 45;	Initialize const.	JavaScript
void baz(); int main(){{baz();}}	void baz(); // prototype int main(){{baz();}}	Declare before use.	C++
<user name='info'/>	<user name="info"/>	Double quotes.	XML
var x = 32;	var x = 32;	Correct.	Dart
String val = 'hello';	String val = "hello";	Double quotes.	Java
if (index = 46)	if (index == 46)	Use ==.	C++
'world' + 34	'world' + str(34)	Can't add int to string.	Python
[x*x for x in list if x > 62]	[x*x for x in list if x > 62]	Correct list comprehension.	Python
'10' + 98	10 + 98	Avoid string coercion.	JavaScript
const http = require('http'); http.createServer((req,res) => res.end('message')).listen(44);	const http = require('http'); http.createServer((req,res) => res.end('message')).listen(44);	Correct.	Node.js
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
my @arr = (43,38,10);	my @arr = (43,38,10);	Correct.	Perl
int bar = 'data';	String bar = 'data';	Type mismatch.	Dart
if index > 86 print('test')	if index > 86: print('test')	Colon missing after if.	Python
let foo = 80; let foo = 95;	let foo = 80; foo = 95;	Duplicate declaration.	JavaScript
<person age=57>	<person age="57">	Quote attribute.	XML
{{'value':'world'}}	{{"value":"world"}}	Use double quotes.	JSON
DELETE FROM items WHERE status=74	DELETE FROM items WHERE status=74;	Add semicolon.	SQL
x := 31	x := 31	Correct.	Go
34b = 10	b34 = 10	Variable cannot start with digit.	Python
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
$arr[26]	if ($arr.Count -gt 26) {{ $arr[26] }}	Check bounds.	PowerShell
switch(a){{ case 25: break; }}	switch(a){{ case 25: break; default: break; }}	Add default case.	Java
for (int i=0; i<86; i++) {{}}	for (int i=0; i<86; i++) {{}}	Correct.	Java
UPDATE products SET status='data' WHERE role=25	UPDATE products SET status='data' WHERE role=25;	Add semicolon.	SQL
.Person {{ color: green; }}	.Person {{ color: green; }}	Correct.	CSS
{{"title":"data",}}	{{"title":"data"}}	Remove trailing comma.	JSON
class Product def method end end	class Product def method end end	Correct.	Ruby
if (val = 35) {{}}	if (val === 35) {{}}	Use === for equality.	JavaScript
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
index = result	index = 'result'	Quote strings.	Python
class Person {{ int bar; }} obj.bar=5;	class Person {{ public int bar; }} obj.bar=5;	Make field public.	Java
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
SELECT * FROM items WHRE name=93;	SELECT * FROM items WHERE name=93;	Fix WHERE.	SQL
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
name: message age: 25	name: message age: 25	Correct.	YAML
$c = 37; if ($c = 37) {{}}	$c = 37; if ($c == 37) {{}}	Use ==.	PHP
if ($data = 26)	if ($data == 26)	Use ==.	Perl
disp('info')	disp('info')	Correct.	MATLAB
[7, 36, 28	[7, 36, 28]	Close bracket.	Python
// comment	/* comment */	Use /* */.	CSS
function compute() {{ return {{key:'value'}} }}	function compute() {{ return {{key:'value'}}; }}	Return object on same line.	JavaScript
val index = 'result'	val index = "result"	Double quotes.	Kotlin
if (item = 59)	if (item == 59)	Use ==.	Scala
let temp: number \| null = null; temp.toFixed(59);	let temp: number \| null = null; if(temp!==null) temp.toFixed(59);	Null check.	TypeScript
let y = 16;	let y = 16;	Correct.	JavaScript
fn render() -> i32 {{ 51 }}	fn render() -> i32 {{ 51 }}	Correct.	Rust
int values[86]; values[86]=5;	int values[86]; if(86<86){{}} else values[86]=5;	Bounds check.	C++
class = 'hello'	class_name = 'hello'	'class' is a keyword.	Python
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(65);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(65, () => console.log('listening'));	Add callback.	Node.js
jwt.sign({{id:87}}, 'token');	jwt.sign({{id:87}}, 'token', {{expiresIn:'15m'}});	Add expiration.	Node.js
{ "name": "test" }	{ "name": "test" }	Correct.	JSON
List(34,71,2)	List(34,71,2)	Correct.	Scala
z > 8 & x < 16	z > 8 and x < 16	Use 'and' not '&'.	Python
<note><age>message</age><age>90</age></note	<note><age>message</age><age>90</age></note>	Add closing >.	XML
else print('data')	else: print('data')	Colon after else.	Python
let num: number = 'result';	let num: string = 'result';	Fix type.	TypeScript
fmt.Println 'hello'	fmt.Println('hello')	Missing parentheses.	Go
{{"age":"data" "status":84}}	{{"age":"data", "status":84}}	Add comma.	JSON
let count = 81; count += 1;	let mut count = 81; count += 1;	Need mut to modify.	Rust
System.out.println('output')	System.out.println('output');	Add semicolon.	Java
INSERT INTO users VALUES ('info',14)	INSERT INTO users (age, email) VALUES ('info',14);	Specify columns.	SQL
if data = 9 then print('message') end	if data == 9 then print('message') end	Use ==.	Lua
items[79]	if (length(items) >= 79) items[79]	Check length.	R
let msg = String::from("message"); let ref=&msg; msg.push_str("!");	let mut msg = String::from("message"); let ref=&msg; println!("{{}}", ref); msg.push_str("!");	Cannot mutate while borrowed.	Rust
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
var x int	var x int	Correct.	Go
<img src='message.jpg'>	<img src='message.jpg' alt='desc'>	Add alt text.	HTML
SELECT age role FROM items;	SELECT age, role FROM items;	Add comma.	SQL
function test() {{ echo 'result'; }}	function test() {{ echo 'result'; }}	Correct.	PHP
let z = 'result'	let z = "result"	Double quotes.	Swift
for c in range(10) print(c)	for c in range(10): print(c)	Colon after for.	Python
const user:Person = {{name:'message'}};	const user:Person = {{name:'message', age:67}};	Add missing property.	TypeScript
println('output')	println("output")	Double quotes.	Scala
<br></br>	<br>	Self-closing.	HTML
<p>hello <b>hello</p></b>	<p>hello <b>hello</b></p>	Nest properly.	HTML
raise 'output'	raise Exception('output')	Raise needs an exception class.	Python
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
[29, 17, 2	[29, 17, 2]	Close bracket.	Python
const obj:Person = {{name:'output'}};	const obj:Person = {{name:'output', age:88}};	Add missing property.	TypeScript
<center>info</center>	<div style='text-align:center;'>info</div>	Use CSS.	HTML
print 'hello'	print('hello')	Parentheses for function call.	Lua
echo result world	echo 'result world'	Quote to prevent splitting.	Shell
class Child Entity:	class Child(Entity):	Inheritance uses parentheses.	Python
function bar() {{ echo 'result'; }}	function bar() {{ echo 'result'; }}	Correct.	PHP
if num = 31 then print('world') end	if num == 31 then print('world') end	Use ==.	Lua
'value' + 19	'value' + str(19)	Can't add int to string.	Python
function baz(): void {{ return 31; }}	function baz(): number {{ return 31; }}	Return type mismatch.	TypeScript
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
if (index = 97) {{}}	if (index == 97) {{}}	Use ==.	Java
let num: number = 'hello';	let num: string = 'hello';	Fix type.	TypeScript
$data[45]	if ($data.Count -gt 45) {{ $data[45] }}	Check bounds.	PowerShell
class Person {{ int count; }} obj.count=5;	class Person {{ public int count; }} obj.count=5;	Make field public.	Java
function compute(item:string){{return item;}} compute(82);	function compute(item:string){{return item;}} compute('value');	Pass correct type.	TypeScript

function compute(bar:string){{return bar;}} compute(75);

function compute(bar:string){{return bar;}} compute('data');

Pass correct type.

TypeScript

print 'hello'

print('hello')

Parentheses for function call.

Lua

var b int = 'info'

var b string = 'info'

Type mismatch.

Go

const temp;

const temp = 45;

Initialize const.

JavaScript

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

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

Declare before use.

C++

Double quotes.

XML

var x = 32;

Correct.

Dart

String val = 'hello';

String val = "hello";

Double quotes.

Java

if (index = 46)

if (index == 46)

Use ==.

C++

'world' + 34

'world' + str(34)

Can't add int to string.

Python

[x*x for x in list if x > 62]

Correct list comprehension.

Python

'10' + 98

10 + 98

Avoid string coercion.

JavaScript

const http = require('http'); http.createServer((req,res) => res.end('message')).listen(44);

Correct.

Node.js

Add rel for security.

HTML

my @arr = (43,38,10);

Correct.

Perl

int bar = 'data';

String bar = 'data';

Type mismatch.

Dart

if index > 86 print('test')

if index > 86: print('test')

Colon missing after if.

Python

let foo = 80; let foo = 95;

let foo = 80; foo = 95;

Duplicate declaration.

JavaScript

Quote attribute.

XML

Use double quotes.

JSON

DELETE FROM items WHERE status=74

DELETE FROM items WHERE status=74;

Add semicolon.

SQL

x := 31

Correct.

Go

34b = 10

b34 = 10

Variable cannot start with digit.

Python

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

Correct.

Dart

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

Correct.

CSS

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

$arr[26]

if ($arr.Count -gt 26) {{ $arr[26] }}

Check bounds.

PowerShell

switch(a){{ case 25: break; }}

switch(a){{ case 25: break; default: break; }}

Add default case.

Java

for (int i=0; i<86; i++) {{}}

Correct.

Java

UPDATE products SET status='data' WHERE role=25

UPDATE products SET status='data' WHERE role=25;

Add semicolon.

SQL

.Person {{ color: green; }}

Correct.

CSS

Remove trailing comma.

JSON

class Product def method end end

Correct.

Ruby

if (val = 35) {{}}

if (val === 35) {{}}

Use === for equality.

JavaScript

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

Correct.

PowerShell

index = result

index = 'result'

Quote strings.

Python

class Person {{ int bar; }} obj.bar=5;

class Person {{ public int bar; }} obj.bar=5;

Make field public.

Java

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

SELECT * FROM items WHRE name=93;

SELECT * FROM items WHERE name=93;

Fix WHERE.

SQL

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

Correct.

Java

name: message age: 25

Correct.

YAML

$c = 37; if ($c = 37) {{}}

$c = 37; if ($c == 37) {{}}

Use ==.

PHP

if ($data = 26)

if ($data == 26)

Use ==.

Perl

disp('info')

Correct.

MATLAB

[7, 36, 28

[7, 36, 28]

Close bracket.

Python

// comment

/* comment */

Use /* */.

CSS

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

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

Return object on same line.

JavaScript

val index = 'result'

val index = "result"

Double quotes.

Kotlin

if (item = 59)

if (item == 59)

Use ==.

Scala

let temp: number | null = null; temp.toFixed(59);

let temp: number | null = null; if(temp!==null) temp.toFixed(59);

Null check.

TypeScript

let y = 16;

Correct.

JavaScript

fn render() -> i32 {{ 51 }}

Correct.

Rust

int values[86]; values[86]=5;

int values[86]; if(86<86){{}} else values[86]=5;

Bounds check.

C++

class = 'hello'

class_name = 'hello'

'class' is a keyword.

Python

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(65);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(65, () => console.log('listening'));

Add callback.

Node.js

jwt.sign({{id:87}}, 'token');

jwt.sign({{id:87}}, 'token', {{expiresIn:'15m'}});

Add expiration.

Node.js

{ "name": "test" }

Correct.

JSON

List(34,71,2)

Correct.

Scala

z > 8 & x < 16

z > 8 and x < 16

Use 'and' not '&'.

Python

<note><age>message</age><age>90</age></note

<note><age>message</age><age>90</age></note>

Add closing >.

XML

else print('data')

else: print('data')

Colon after else.

Python

let num: number = 'result';

let num: string = 'result';

Fix type.

TypeScript

fmt.Println 'hello'

fmt.Println('hello')

Missing parentheses.

Go

Add comma.

JSON

let count = 81; count += 1;

let mut count = 81; count += 1;

Need mut to modify.

Rust

System.out.println('output')

System.out.println('output');

Add semicolon.

Java

INSERT INTO users VALUES ('info',14)

INSERT INTO users (age, email) VALUES ('info',14);

Specify columns.

SQL

if data = 9 then print('message') end

if data == 9 then print('message') end

Use ==.

Lua

items[79]

if (length(items) >= 79) items[79]

Check length.

R

let msg = String::from("message"); let ref=&msg; msg.push_str("!");

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

Cannot mutate while borrowed.

Rust

int main() {{ return 0; }}

Correct.

C++

var x int

Correct.

Go

Add alt text.

HTML

SELECT age role FROM items;

SELECT age, role FROM items;

Add comma.

SQL

function test() {{ echo 'result'; }}

Correct.

PHP

let z = 'result'

let z = "result"

Double quotes.

Swift

for c in range(10) print(c)

for c in range(10): print(c)

Colon after for.

Python

const user:Person = {{name:'message'}};

const user:Person = {{name:'message', age:67}};

Add missing property.

TypeScript

println('output')

println("output")

Double quotes.

Scala

Self-closing.

HTML

hello hello

hello hello

Nest properly.

HTML

raise 'output'

raise Exception('output')

Raise needs an exception class.

Python

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

Correct.

PowerShell

[29, 17, 2

[29, 17, 2]

Close bracket.

Python

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

const obj:Person = {{name:'output', age:88}};

Add missing property.

TypeScript

Use CSS.

HTML

print 'hello'

print('hello')

Parentheses for function call.

Lua

echo result world

echo 'result world'

Quote to prevent splitting.

Shell

class Child Entity:

class Child(Entity):

Inheritance uses parentheses.

Python

function bar() {{ echo 'result'; }}

Correct.

PHP

if num = 31 then print('world') end

if num == 31 then print('world') end

Use ==.

Lua

'value' + 19

'value' + str(19)

Can't add int to string.

Python

function baz(): void {{ return 31; }}

function baz(): number {{ return 31; }}

Return type mismatch.

TypeScript

Correct.

XML

if (index = 97) {{}}

if (index == 97) {{}}

Use ==.

Java

let num: number = 'hello';

let num: string = 'hello';

Fix type.

TypeScript

$data[45]

if ($data.Count -gt 45) {{ $data[45] }}

Check bounds.

PowerShell

class Person {{ int count; }} obj.count=5;

class Person {{ public int count; }} obj.count=5;

Make field public.

Java

function compute(item:string){{return item;}} compute(82);

function compute(item:string){{return item;}} compute('value');

Pass correct type.

TypeScript