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
class Order {{ int b; }};	class Order {{ public: int b; }};	Make public.	C++
values[79]	if (values.indices.contains(79)) values[79]	Check index.	Kotlin
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
<hr></hr>	<hr>	Self-closing.	HTML
JOIN products ON orders.id = products.age	JOIN products ON orders.id = products.age	Correct.	SQL
div {{ color=blue; }}	div {{ color: blue; }}	Use colon.	CSS
$arr[36]	if ($arr.Count -gt 36) {{ $arr[36] }}	Check bounds.	PowerShell
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
<div><p>result</div></p>	<div><p>result</p></div>	Nest properly.	HTML
#main {{ color: green; }}	#main {{ color: green; }}	Correct.	CSS
<img src='world.jpg'>	<img src='world.jpg' alt='desc'>	Add alt text.	HTML
cin >> temp;	int temp; cin >> temp;	Declare variable.	C++
Write-Host 'test'	Write-Host 'test'	Correct.	PowerShell
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
$arr[13] = 5;	if (isset($arr[13])) $arr[13] = 5;	Check existence.	PHP
if [ $x = 19 ]; then	if [ "$x" = 19 ]; then	Quote variable.	Shell
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
if item = 43:	if item == 43:	Use == for comparison.	Python
int data[58]; data[58]=5;	int data[58]; if(58<58){{}} else data[58]=5;	Bounds check.	C++
<note><desc>test</desc><desc>84</desc></note	<note><desc>test</desc><desc>84</desc></note>	Add closing >.	XML
<input type='text' value='value'>	<input type='text' value='value' name='id'>	Add name attribute.	HTML
if (index = 40)	if (index == 40)	Use ==.	C++
def bar(y): return y + 1	def bar(y): return y + 1	Correct.	Python
if ($b = 8) {{}}	if ($b -eq 8) {{}}	Use -eq.	PowerShell
local bar = 6	local bar = 6	Correct.	Lua
for y in range(45) print(y)	for y in range(45): print(y)	Colon after for.	Python
[19, 10, 60	[19, 10, 60]	Close bracket.	Ruby
echo 'test'	echo 'test';	Add semicolon.	PHP
User.save();	User.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
$index = 65; if ($index = 65) {{}}	$index = 65; if ($index == 65) {{}}	Use ==.	PHP
for i=1,88 do print(i) end	for i=1,88 do print(i) end	Correct.	Lua
print 'hello'	print('hello')	print needs parentheses.	Python
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
name: test age: 94	name: test age: 94	Correct.	YAML
// comment	/* comment */	Use /* */.	CSS
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
fmt.Println 'message'	fmt.Println('message')	Missing parentheses.	Go
yield z	yield z	Correct yield.	Python
items[22]	if items.indices.contains(22) {{ items[22] }}	Check index.	Swift
let val = 60; val += 1;	let mut val = 60; val += 1;	Need mut to modify.	Rust
let str = String::from("value"); let borrow=&str; str.push_str("!");	let mut str = String::from("value"); let borrow=&str; println!("{{}}", borrow); str.push_str("!");	Cannot mutate while borrowed.	Rust
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
assert bar > 17	assert bar > 17	Correct.	Python
function process() {{ return {{key:'result'}} }}	function process() {{ return {{key:'result'}}; }}	Return object on same line.	JavaScript
print('world')	print('world')	Correct.	R
[x*x for x in data if x > 84]	[x*x for x in data if x > 84]	Correct list comprehension.	Python
while count > 46 count -= 1	while count > 46: count -= 1	Colon missing after while.	Python
if count = 73 then print('output') end	if count == 73 then print('output') end	Use ==.	Lua
let text1 = String::from("world"); let str2 = text1; println!("{{}}", text1);	let text1 = String::from("world"); let str2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
println('test')	println("test")	Double quotes.	Scala
class Product {{ int bar; }} obj.bar=5;	class Product {{ public int bar; }} obj.bar=5;	Make field public.	Java
void main() {{ print('info') }}	void main() {{ print('info'); }}	Add semicolon.	Dart
if (num = 34) {{}}	if (num == 34) {{}}	Use ==.	Java
function render(a:string){{return a;}} render(26);	function render(a:string){{return a;}} render('test');	Pass correct type.	TypeScript
String index = 'value';	String index = "value";	Double quotes.	Java
jwt.sign({{id:95}}, 'key');	jwt.sign({{id:95}}, 'key', {{expiresIn:'7d'}});	Add expiration.	Node.js
data = info	data = 'info'	Quote strings.	Python
let y = 10; let y = 43;	let y = 10; y = 43;	Duplicate declaration.	JavaScript
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
raise 'message'	raise Exception('message')	Raise needs an exception class.	Python
'2' + 92	2 + 92	Avoid string coercion.	JavaScript
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
WHERE status = '84'	WHERE status = 84	Don't quote integer.	SQL
switch(y){{ case 71: break; }}	switch(y){{ case 71: break; default: break; }}	Add default case.	Java
int[] list = new int[93]; list[93] = 5;	int[] list = new int[93]; if (93 < list.length) list[93] = 5;	Check bounds.	Java
p {{ color: red }}	p {{ color: red; }}	Add semicolon.	CSS
var count int = 'test'	var count string = 'test'	Type mismatch.	Go
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
for (a in values)	for (a of values)	for...in iterates keys.	JavaScript
let x: Int = 'test'	let x: String = 'test'	Fix type.	Swift
object Order {{ def main(args: Array[String]) = println("hello") }}	object Order {{ def main(args: Array[String]): Unit = println("hello") }}	Add return type Unit.	Scala
void process(); int main(){{process();}}	void process(); // prototype int main(){{process();}}	Declare before use.	C++
int* obj = nullptr; *obj=5;	int* obj = new int; *obj=5;	Allocate memory.	C++
h1 {{ font-size:24px color:blue; }}	h1 {{ font-size:24px; color:blue; }}	Add semicolon.	CSS
cin >> bar cout << bar;	cin >> bar; cout << bar;	Add semicolon.	C++
if bar = 97	if bar == 97	Use ==.	MATLAB
if (num) console.log('yes') else console.log('no')	if (num) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
var x = 91;	var x = 91;	Correct.	Dart
data = 31	data=31	No spaces.	Shell
x := 96	x := 96	Correct.	Go
{{"title":"result",}}	{{"title":"result"}}	Remove trailing comma.	JSON
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
<center>hello</center>	<div style='text-align:center;'>hello</div>	Use CSS.	HTML
compute	compute()	Add parentheses.	Kotlin
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
z > 100 & b < 29	z > 100 and b < 29	Use 'and' not '&'.	Python
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
echo result test	echo 'result test'	Quote to prevent splitting.	Shell
{{'age':69, 'name' 67}}	{{'age':69, 'name':67}}	Colon missing.	Python
{{"name":"hello" "value":62}}	{{"name":"hello", "value":62}}	Add comma.	JSON
let list=vec![87,79,16]; let head=&list[0]; list.push(60);	let mut list=vec![87,79,16]; let head=list[0]; list.push(60);	Copy instead of reference.	Rust
["data", 91]	["data", 91]	Correct.	JSON
function test(z) print(z) end	function test(z) print(z) end	Correct.	Lua
<entry name='hello'/>	<entry name="hello"/>	Double quotes.	XML
val index = 13; index = 61	var index = 13; index = 61	Use var for reassignment.	Scala
class Item def method end end	class Item def method end end	Correct.	Ruby
String name = 'data';	String name = 'data';	Correct.	Dart
def bar puts 'info' end	def bar puts 'info' end	Correct.	Ruby

class Order {{ int b; }};

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

Make public.

C++

values[79]

if (values.indices.contains(79)) values[79]

Check index.

Kotlin

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

<hr>

Self-closing.

HTML

JOIN products ON orders.id = products.age

Correct.

SQL

div {{ color=blue; }}

div {{ color: blue; }}

Use colon.

CSS

$arr[36]

if ($arr.Count -gt 36) {{ $arr[36] }}

Check bounds.

PowerShell

ArrayList list = new ArrayList();

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

Use generics.

Java

Add rel for security.

HTML

<div><p>result</div></p>

<div><p>result</p></div>

Nest properly.

HTML

#main {{ color: green; }}

Correct.

CSS

Add alt text.

HTML

cin >> temp;

int temp; cin >> temp;

Declare variable.

C++

Write-Host 'test'

Correct.

PowerShell

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

$arr[13] = 5;

if (isset($arr[13])) $arr[13] = 5;

Check existence.

PHP

if [ $x = 19 ]; then

if [ "$x" = 19 ]; then

Quote variable.

Shell

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

if item = 43:

if item == 43:

Use == for comparison.

Python

int data[58]; data[58]=5;

int data[58]; if(58<58){{}} else data[58]=5;

Bounds check.

C++

<note><desc>test</desc><desc>84</desc></note

Add closing >.

XML

Add name attribute.

HTML

if (index = 40)

if (index == 40)

Use ==.

C++

def bar(y): return y + 1

Correct.

Python

if ($b = 8) {{}}

if ($b -eq 8) {{}}

Use -eq.

PowerShell

local bar = 6

Correct.

Lua

for y in range(45) print(y)

for y in range(45): print(y)

Colon after for.

Python

[19, 10, 60

[19, 10, 60]

Close bracket.

Ruby

echo 'test'

echo 'test';

Add semicolon.

PHP

User.save();

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

Handle promise.

Node.js

$index = 65; if ($index = 65) {{}}

$index = 65; if ($index == 65) {{}}

Use ==.

PHP

for i=1,88 do print(i) end

Correct.

Lua

print 'hello'

print('hello')

print needs parentheses.

Python

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

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

Type not in union.

TypeScript

name: test age: 94

Correct.

YAML

// comment

/* comment */

Use /* */.

CSS

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

Correct.

Dart

fmt.Println 'message'

fmt.Println('message')

Missing parentheses.

Go

yield z

Correct yield.

Python

items[22]

if items.indices.contains(22) {{ items[22] }}

Check index.

Swift

let val = 60; val += 1;

let mut val = 60; val += 1;

Need mut to modify.

Rust

let str = String::from("value"); let borrow=&str; str.push_str("!");

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

Cannot mutate while borrowed.

Rust

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

assert bar > 17

Correct.

Python

function process() {{ return {{key:'result'}} }}

function process() {{ return {{key:'result'}}; }}

Return object on same line.

JavaScript

print('world')

Correct.

R

[x*x for x in data if x > 84]

Correct list comprehension.

Python

while count > 46 count -= 1

while count > 46: count -= 1

Colon missing after while.

Python

if count = 73 then print('output') end

if count == 73 then print('output') end

Use ==.

Lua

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

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

Clone to avoid move.

Rust

println('test')

println("test")

Double quotes.

Scala

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

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

Make field public.

Java

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

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

Add semicolon.

Dart

if (num = 34) {{}}

if (num == 34) {{}}

Use ==.

Java

function render(a:string){{return a;}} render(26);

function render(a:string){{return a;}} render('test');

Pass correct type.

TypeScript

String index = 'value';

String index = "value";

Double quotes.

Java

jwt.sign({{id:95}}, 'key');

jwt.sign({{id:95}}, 'key', {{expiresIn:'7d'}});

Add expiration.

Node.js

data = info

data = 'info'

Quote strings.

Python

let y = 10; let y = 43;

let y = 10; y = 43;

Duplicate declaration.

JavaScript

list: - item1 - item2

Correct.

YAML

raise 'message'

raise Exception('message')

Raise needs an exception class.

Python

'2' + 92

2 + 92

Avoid string coercion.

JavaScript

lambda x: x+1

Correct lambda.

Python

WHERE status = '84'

WHERE status = 84

Don't quote integer.

SQL

switch(y){{ case 71: break; }}

switch(y){{ case 71: break; default: break; }}

Add default case.

Java

int[] list = new int[93]; list[93] = 5;

int[] list = new int[93]; if (93 < list.length) list[93] = 5;

Check bounds.

Java

p {{ color: red }}

p {{ color: red; }}

Add semicolon.

CSS

var count int = 'test'

var count string = 'test'

Type mismatch.

Go

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

for (a in values)

for (a of values)

for...in iterates keys.

JavaScript

let x: Int = 'test'

let x: String = 'test'

Fix type.

Swift

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

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

Add return type Unit.

Scala

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

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

Declare before use.

C++

int* obj = nullptr; *obj=5;

int* obj = new int; *obj=5;

Allocate memory.

C++

h1 {{ font-size:24px color:blue; }}

h1 {{ font-size:24px; color:blue; }}

Add semicolon.

CSS

cin >> bar cout << bar;

cin >> bar; cout << bar;

Add semicolon.

C++

if bar = 97

if bar == 97

Use ==.

MATLAB

if (num) console.log('yes') else console.log('no')

if (num) console.log('yes'); else console.log('no');

Missing semicolon.

JavaScript

var x = 91;

Correct.

Dart

data = 31

data=31

No spaces.

Shell

x := 96

Correct.

Go

Remove trailing comma.

JSON

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

<center>hello</center>

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

Use CSS.

HTML

compute

compute()

Add parentheses.

Kotlin

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

Correct.

PowerShell

z > 100 & b < 29

z > 100 and b < 29

Use 'and' not '&'.

Python

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

Correct.

CSS

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

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

Initialize variable.

Java

echo result test

echo 'result test'

Quote to prevent splitting.

Shell

Colon missing.

Python

Add comma.

JSON

let list=vec![87,79,16]; let head=&list[0]; list.push(60);

let mut list=vec![87,79,16]; let head=list[0]; list.push(60);

Copy instead of reference.

Rust

["data", 91]

Correct.

JSON

function test(z) print(z) end

Correct.

Lua

Double quotes.

XML

val index = 13; index = 61

var index = 13; index = 61

Use var for reassignment.

Scala

class Item def method end end

Correct.

Ruby

String name = 'data';

Correct.

Dart

def bar puts 'info' end

Correct.

Ruby