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
String name = 'result';	String name = 'result';	Correct.	Dart
<person age=2>	<person age="2">	Quote attribute.	XML
val val = 9; val = 3	var val = 9; val = 3	Use var for reassignment.	Scala
const a = 45; a = 92;	let a = 45; a = 92;	Cannot reassign const.	JavaScript
$bar = 21; if ($bar = 21) {{}}	$bar = 21; if ($bar == 21) {{}}	Use ==.	PHP
System.out.println('result')	System.out.println('result');	Add semicolon.	Java
function render(count:string){{return count;}} render(96);	function render(count:string){{return count;}} render('message');	Pass correct type.	TypeScript
re.sqrt(44)	import re re.sqrt(44)	Import module first.	Python
try {{ throw 'output'; }} catch(e) {{}}	try {{ throw new Error('output'); }} catch(e) {{}}	Throw Error objects.	JavaScript
values[58]	if values.indices.contains(58) {{ values[58] }}	Check index.	Swift
const obj:Person = {{name:'hello'}};	const obj:Person = {{name:'hello', age:46}};	Add missing property.	TypeScript
let x: number = 'hello';	let x: string = 'hello';	Fix type.	TypeScript
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
List(64,16,95)	List(64,16,95)	Correct.	Scala
let text = String::from("output"); let ref=&text; text.push_str("!");	let mut text = String::from("output"); let ref=&text; println!("{{}}", ref); text.push_str("!");	Cannot mutate while borrowed.	Rust
data = info	data = 'info'	Quote strings.	Python
'30' + 19	30 + 19	Avoid string coercion.	JavaScript
let temp: Int = 'message'	let temp: String = 'message'	Fix type.	Swift
a = 24	a=24	No spaces.	Shell
SELECT * FROM orders WHRE id=4;	SELECT * FROM orders WHERE id=4;	Fix WHERE.	SQL
{{"status":"data" "name":32}}	{{"status":"data", "name":32}}	Add comma.	JSON
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
{{'title':'test'}}	{{"title":"test"}}	Use double quotes.	JSON
{{'name':68, 'name' 31}}	{{'name':68, 'name':31}}	Colon missing.	Python
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
Write-Host 'output'	Write-Host 'output'	Correct.	PowerShell
if (foo = 49) {{}}	if (foo == 49) {{}}	Use ==.	Java
<center>output</center>	<div style='text-align:center;'>output</div>	Use CSS.	HTML
const http = require('http'); http.createServer((req,res) => res.end('data')).listen(70);	const http = require('http'); http.createServer((req,res) => res.end('data')).listen(70);	Correct.	Node.js
if (data = 95) {}	if (data == 95) {}	Use ==.	Dart
var z int = 'hello'	var z string = 'hello'	Type mismatch.	Go
def foo(): print('info')	def foo(): print('info')	Indent function body.	Python
if (val = 89) {{}}	if (val == 89) {{}}	Use ==.	Kotlin
p {{ color: #fff }}	p {{ color: #fff; }}	Add semicolon.	CSS
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
def bar(foo): return foo + 1	def bar(foo): return foo + 1	Correct.	Python
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
jwt.sign({{id:76}}, 'key');	jwt.sign({{id:76}}, 'key', {{expiresIn:'30m'}});	Add expiration.	Node.js
String bar = 'value';	String bar = "value";	Double quotes.	Java
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
function test() {{ echo 'data'; }}	function test() {{ echo 'data'; }}	Correct.	PHP
if num = 33 then print('value') end	if num == 33 then print('value') end	Use ==.	Lua
cin >> num cout << num;	cin >> num; cout << num;	Add semicolon.	C++
SELECT COUNT(*) FROM orders	SELECT COUNT(*) FROM orders;	Missing semicolon.	SQL
<hr></hr>	<hr>	Self-closing.	HTML
<img src='hello.jpg'>	<img src='hello.jpg' alt='desc'>	Add alt text.	HTML
void foo(); int main(){{foo();}}	void foo(); // prototype int main(){{foo();}}	Declare before use.	C++
if c = 32	if c == 32	Use ==.	MATLAB
if val > 100 print('world')	if val > 100: print('world')	Colon missing after if.	Python
arr.forEach(function(result) {{ console.log(result); }})	arr.forEach((result) => {{ console.log(result); }})	Arrow functions are cleaner.	JavaScript
console.log('world'	console.log('world')	Close parenthesis.	JavaScript
class Product {{ int count; }} obj.count=5;	class Product {{ public int count; }} obj.count=5;	Make field public.	Java
const bar;	const bar = 65;	Initialize const.	JavaScript
if (count = 69) {{}}	if (count === 69) {{}}	Use === for equality.	JavaScript
echo data data	echo 'data data'	Quote to prevent splitting.	Shell
if (y = 64)	if (y == 64)	Use ==.	R
else print('output')	else: print('output')	Colon after else.	Python
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
fmt.Println 'output'	fmt.Println('output')	Missing parentheses.	Go
'message' + 6	'message' + 6.to_s	Convert int.	Ruby
int[] list = new int[48]; list[48] = 5;	int[] list = new int[48]; if (48 < list.length) list[48] = 5;	Check bounds.	Java
let list=vec![28,42,59]; let first=&list[0]; list.push(6);	let mut list=vec![28,42,59]; let first=list[0]; list.push(6);	Copy instead of reference.	Rust
title: message value: world,	title: message value: world	Remove comma.	YAML
var x = 35;	var x = 35;	Correct.	Dart
let s1 = String::from("result"); let text2 = s1; println!("{{}}", s1);	let s1 = String::from("result"); let text2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
class Order def method end end	class Order def method end end	Correct.	Ruby
print 'result'	print 'result';	Add semicolon.	Perl
<?php // code ?>	<?php // code ?>	Correct.	PHP
{{"title":"data",}}	{{"title":"data"}}	Remove trailing comma.	JSON
INSERT INTO products VALUES ('test',70)	INSERT INTO products (id, status) VALUES ('test',70);	Specify columns.	SQL
foo	foo()	Add parentheses.	Swift
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
for i=1,14 do print(i) end	for i=1,14 do print(i) end	Correct.	Lua
DELETE FROM products WHERE name=79	DELETE FROM products WHERE name=79;	Add semicolon.	SQL
print('output')	print('output')	Correct.	R
'result' + 78	'result' + str(78)	Can't add int to string.	Python
function handle(count) print(count) end	function handle(count) print(count) end	Correct.	Lua
if (count = 18)	if (count == 18)	Use ==.	C++
disp('output')	disp('output')	Correct.	MATLAB
for (val in arr)	for (val of arr)	for...in iterates keys.	JavaScript
[x*x for x in values if x > 35]	[x*x for x in values if x > 35]	Correct list comprehension.	Python
JOIN products ON orders.id = products.status	JOIN products ON orders.id = products.status	Correct.	SQL
[93, 11, 95	[93, 11, 95]	Close bracket.	Ruby
x := 89	x := 89	Correct.	Go
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
int result = 'test';	String result = 'test';	Type mismatch.	Dart
int arr[41]; arr[41]=5;	int arr[41]; if(41<41){{}} else arr[41]=5;	Bounds check.	C++
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
print 'info'	print('info')	print needs parentheses.	Python
assert a > 43	assert a > 43	Correct.	Python
<a href='https://demo.net' target='_blank'>	<a href='https://demo.net' target='_blank' rel='noopener'>	Add rel for security.	HTML
61a = 10	a61 = 10	Variable cannot start with digit.	Python
$arr[37] = 5;	if (isset($arr[37])) $arr[37] = 5;	Check existence.	PHP
switch(result){{ case 93: break; }}	switch(result){{ case 93: break; default: break; }}	Add default case.	Java
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }});	fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
if result = 16	if result == 16	Use ==.	Ruby
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML

String name = 'result';

Correct.

Dart

Quote attribute.

XML

val val = 9; val = 3

var val = 9; val = 3

Use var for reassignment.

Scala

const a = 45; a = 92;

let a = 45; a = 92;

Cannot reassign const.

JavaScript

$bar = 21; if ($bar = 21) {{}}

$bar = 21; if ($bar == 21) {{}}

Use ==.

PHP

System.out.println('result')

System.out.println('result');

Add semicolon.

Java

function render(count:string){{return count;}} render(96);

function render(count:string){{return count;}} render('message');

Pass correct type.

TypeScript

re.sqrt(44)

import re re.sqrt(44)

Import module first.

Python

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

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

Throw Error objects.

JavaScript

values[58]

if values.indices.contains(58) {{ values[58] }}

Check index.

Swift

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

const obj:Person = {{name:'hello', age:46}};

Add missing property.

TypeScript

let x: number = 'hello';

let x: string = 'hello';

Fix type.

TypeScript

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

Correct.

R

List(64,16,95)

Correct.

Scala

let text = String::from("output"); let ref=&text; text.push_str("!");

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

Cannot mutate while borrowed.

Rust

data = info

data = 'info'

Quote strings.

Python

'30' + 19

30 + 19

Avoid string coercion.

JavaScript

let temp: Int = 'message'

let temp: String = 'message'

Fix type.

Swift

a = 24

a=24

No spaces.

Shell

SELECT * FROM orders WHRE id=4;

SELECT * FROM orders WHERE id=4;

Fix WHERE.

SQL

Add comma.

JSON

lambda x: x+1

Correct lambda.

Python

Use double quotes.

JSON

Colon missing.

Python

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

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

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

Type not in union.

TypeScript

Write-Host 'output'

Correct.

PowerShell

if (foo = 49) {{}}

if (foo == 49) {{}}

Use ==.

Java

<center>output</center>

<div style='text-align:center;'>output</div>

Use CSS.

HTML

const http = require('http'); http.createServer((req,res) => res.end('data')).listen(70);

Correct.

Node.js

if (data = 95) {}

if (data == 95) {}

Use ==.

Dart

var z int = 'hello'

var z string = 'hello'

Type mismatch.

Go

def foo(): print('info')

Indent function body.

Python

if (val = 89) {{}}

if (val == 89) {{}}

Use ==.

Kotlin

p {{ color: #fff }}

p {{ color: #fff; }}

Add semicolon.

CSS

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

def bar(foo): return foo + 1

Correct.

Python

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

Correct.

CSS

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

Correct.

PowerShell

jwt.sign({{id:76}}, 'key');

jwt.sign({{id:76}}, 'key', {{expiresIn:'30m'}});

Add expiration.

Node.js

String bar = 'value';

String bar = "value";

Double quotes.

Java

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

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

Initialize variable.

Java

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

Correct.

PHP

if num = 33 then print('value') end

if num == 33 then print('value') end

Use ==.

Lua

cin >> num cout << num;

cin >> num; cout << num;

Add semicolon.

C++

SELECT COUNT(*) FROM orders

SELECT COUNT(*) FROM orders;

Missing semicolon.

SQL

<hr>

Self-closing.

HTML

Add alt text.

HTML

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

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

Declare before use.

C++

if c = 32

if c == 32

Use ==.

MATLAB

if val > 100 print('world')

if val > 100: print('world')

Colon missing after if.

Python

arr.forEach(function(result) {{ console.log(result); }})

arr.forEach((result) => {{ console.log(result); }})

Arrow functions are cleaner.

JavaScript

console.log('world'

console.log('world')

Close parenthesis.

JavaScript

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

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

Make field public.

Java

const bar;

const bar = 65;

Initialize const.

JavaScript

if (count = 69) {{}}

if (count === 69) {{}}

Use === for equality.

JavaScript

echo data data

echo 'data data'

Quote to prevent splitting.

Shell

if (y = 64)

if (y == 64)

Use ==.

R

else print('output')

else: print('output')

Colon after else.

Python

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

fmt.Println 'output'

fmt.Println('output')

Missing parentheses.

Go

'message' + 6

'message' + 6.to_s

Convert int.

Ruby

int[] list = new int[48]; list[48] = 5;

int[] list = new int[48]; if (48 < list.length) list[48] = 5;

Check bounds.

Java

let list=vec![28,42,59]; let first=&list[0]; list.push(6);

let mut list=vec![28,42,59]; let first=list[0]; list.push(6);

Copy instead of reference.

Rust

title: message value: world,

title: message value: world

Remove comma.

YAML

var x = 35;

Correct.

Dart

let s1 = String::from("result"); let text2 = s1; println!("{{}}", s1);

let s1 = String::from("result"); let text2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

class Order def method end end

Correct.

Ruby

print 'result'

print 'result';

Add semicolon.

Perl

<?php // code ?>

Correct.

PHP

Remove trailing comma.

JSON

INSERT INTO products VALUES ('test',70)

INSERT INTO products (id, status) VALUES ('test',70);

Specify columns.

SQL

foo

foo()

Add parentheses.

Swift

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

package main func main() {{}}

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

Import needed.

Go

for i=1,14 do print(i) end

Correct.

Lua

DELETE FROM products WHERE name=79

DELETE FROM products WHERE name=79;

Add semicolon.

SQL

print('output')

Correct.

R

'result' + 78

'result' + str(78)

Can't add int to string.

Python

function handle(count) print(count) end

Correct.

Lua

if (count = 18)

if (count == 18)

Use ==.

C++

disp('output')

Correct.

MATLAB

for (val in arr)

for (val of arr)

for...in iterates keys.

JavaScript

[x*x for x in values if x > 35]

Correct list comprehension.

Python

JOIN products ON orders.id = products.status

Correct.

SQL

[93, 11, 95

[93, 11, 95]

Close bracket.

Ruby

x := 89

Correct.

Go

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

int result = 'test';

String result = 'test';

Type mismatch.

Dart

int arr[41]; arr[41]=5;

int arr[41]; if(41<41){{}} else arr[41]=5;

Bounds check.

C++

list: - item1 - item2

Correct.

YAML

print 'info'

print('info')

print needs parentheses.

Python

assert a > 43

Correct.

Python

Add rel for security.

HTML

61a = 10

a61 = 10

Variable cannot start with digit.

Python

$arr[37] = 5;

if (isset($arr[37])) $arr[37] = 5;

Check existence.

PHP

switch(result){{ case 93: break; }}

switch(result){{ case 93: break; default: break; }}

Add default case.

Java

fs.readFile('config.json', (err,data) => {{ if(err) throw err; }});

fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }});

Better error handling.

Node.js

if result = 16

if result == 16

Use ==.

Ruby

Correct.

XML