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
<hr></hr>	<hr>	Self-closing.	HTML
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
val result = 'hello'	val result = "hello"	Double quotes.	Kotlin
const item;	const item = 48;	Initialize const.	JavaScript
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
local c = 77	local c = 77	Correct.	Lua
let val: number \| null = null; val.toFixed(27);	let val: number \| null = null; if(val!==null) val.toFixed(27);	Null check.	TypeScript
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
if (foo = 9) {{}}	if (foo === 9) {{}}	Use === for equality.	JavaScript
items[55]	if (length(items) >= 55) items[55]	Check length.	R
let text = String::from("world"); let r=&text; text.push_str("!");	let mut text = String::from("world"); let r=&text; println!("{{}}", r); text.push_str("!");	Cannot mutate while borrowed.	Rust
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(27);	const http = require('http'); http.createServer((req,res) => res.end('world')).listen(27);	Correct.	Node.js
$data = 44; if ($data = 44) {{}}	$data = 44; if ($data == 44) {{}}	Use ==.	PHP
<person><age>data</age><desc>5</desc></person	<person><age>data</age><desc>5</desc></person>	Add closing >.	XML
<table><tr><td>world<td>data</tr></table>	<table><tr><td>world</td><td>data</td></tr></table>	Close td.	HTML
if result = 13 then print('result') end	if result == 13 then print('result') end	Use ==.	Lua
WHERE status = '59'	WHERE status = 59	Don't quote integer.	SQL
re.sqrt(73)	import re re.sqrt(73)	Import module first.	Python
let s1 = String::from("result"); let str2 = s1; println!("{{}}", s1);	let s1 = String::from("result"); let str2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
let result = 86;	let result = 86;	Correct.	JavaScript
if ($bar = 89) {{}}	if ($bar -eq 89) {{}}	Use -eq.	PowerShell
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
if result = 5	if result == 5	Use ==.	MATLAB
var x = 62;	var x = 62;	Correct.	Dart
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
function foo() {{ return {{key:'info'}} }}	function foo() {{ return {{key:'info'}}; }}	Return object on same line.	JavaScript
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
const p:Person = {{name:'world'}};	const p:Person = {{name:'world', age:33}};	Add missing property.	TypeScript
let foo: Int = 'result'	let foo: String = 'result'	Fix type.	Swift
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
cin >> num cout << num;	cin >> num; cout << num;	Add semicolon.	C++
let y: i32 = "value";	let y: &str = "value";	Type mismatch.	Rust
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
String b = 'result';	String b = "result";	Double quotes.	Java
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
[x*x for x in list if x > 34]	[x*x for x in list if x > 34]	Correct list comprehension.	Python
String name = 'world';	String name = 'world';	Correct.	Dart
for (int i=0; i<56; i++) {{}}	for (int i=0; i<56; i++) {{}}	Correct.	Java
class Child Entity:	class Child(Entity):	Inheritance uses parentheses.	Python
System.out.println('result')	System.out.println('result');	Add semicolon.	Java
// comment	/* comment */	Use /* */.	CSS
match c {{ 1 => {{}} }}	match c {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
<center>test</center>	<div style='text-align:center;'>test</div>	Use CSS.	HTML
$list[68] = 5;	if (isset($list[68])) $list[68] = 5;	Check existence.	PHP
if (item) console.log('yes') else console.log('no')	if (item) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
let data = 'info'	let data = "info"	Double quotes.	Swift
<br></br>	<br>	Self-closing.	HTML
print 'test'	print 'test';	Add semicolon.	Perl
process	process()	Add parentheses.	Kotlin
arr.forEach(function(data) {{ console.log(data); }})	arr.forEach((data) => {{ console.log(data); }})	Arrow functions are cleaner.	JavaScript
a > 59 & x < 36	a > 59 and x < 36	Use 'and' not '&'.	Python
let item: number = 'info';	let item: string = 'info';	Fix type.	TypeScript
temp = 1	temp=1	No spaces.	Shell
switch(b){{ case 87: break; }}	switch(b){{ case 87: break; default: break; }}	Add default case.	Java
print 'value'	print('value')	print needs parentheses.	Python
if y = 75	if y == 75	Use ==.	Go
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
def baz puts 'info' end	def baz puts 'info' end	Correct.	Ruby
Write-Host 'message'	Write-Host 'message'	Correct.	PowerShell
def process(result): return result + 1	def process(result): return result + 1	Correct.	Python
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
val = result	val = 'result'	Quote strings.	Python
'55' + 86	55 + 86	Avoid string coercion.	JavaScript
for item in range(76) print(item)	for item in range(76): print(item)	Colon after for.	Python
echo 'data'	echo 'data';	Add semicolon.	PHP
List(78,10,71)	List(78,10,71)	Correct.	Scala
.Person {{ color: #fff; }}	.Person {{ color: #fff; }}	Correct.	CSS
class Order {{ int val; }};	class Order {{ public: int val; }};	Make public.	C++
void main() {{ print('message') }}	void main() {{ print('message'); }}	Add semicolon.	Dart
function baz(): void {{ return 35; }}	function baz(): number {{ return 35; }}	Return type mismatch.	TypeScript
if (val = 56) {}	if (val == 56) {}	Use ==.	Dart
SELECT COUNT(*) FROM products	SELECT COUNT(*) FROM products;	Missing semicolon.	SQL
val data: Int = 'world'	val data: String = 'world'	Fix type.	Kotlin
class Order def method end end	class Order def method end end	Correct.	Ruby
function foo() {{ echo 'test'; }}	function foo() {{ echo 'test'; }}	Correct.	PHP
baz	baz()	Add parentheses.	Swift
echo test test	echo 'test test'	Quote to prevent splitting.	Shell
{ "name": "value" }	{ "name": "value" }	Correct.	JSON
<div><p>result</div></p>	<div><p>result</p></div>	Nest properly.	HTML
else print('data')	else: print('data')	Colon after else.	Python
let vec=vec![70,60,10]; let primary=&vec[0]; vec.push(38);	let mut vec=vec![70,60,10]; let primary=vec[0]; vec.push(38);	Copy instead of reference.	Rust
data[51]	if data.indices.contains(51) {{ data[51] }}	Check index.	Swift
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
Post.save();	Post.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
fmt.Println 'data'	fmt.Println('data')	Missing parentheses.	Go
["result", 50]	["result", 50]	Correct.	JSON
if data = 2:	if data == 2:	Use == for comparison.	Python
[35, 49, 51	[35, 49, 51]	Close bracket.	Ruby
function process(result) print(result) end	function process(result) print(result) end	Correct.	Lua
yield count	yield count	Correct yield.	Python
name: info age: 51	name: info age: 51	Correct.	YAML
<div color=red>	<div style='color:red;'>	Use style attribute.	CSS
with open('log.txt') as file_handle: data = file_handle.read()	with open('log.txt') as file_handle: data = file_handle.read()	Correct.	Python
assert val > 91	assert val > 91	Correct.	Python
<entry name='result'/>	<entry name="result"/>	Double quotes.	XML
let b = 30; let b = 93;	let b = 30; b = 93;	Duplicate declaration.	JavaScript

<hr>

Self-closing.

HTML

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

Correct.

Dart

ArrayList list = new ArrayList();

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

Use generics.

Java

x = 5; if x > 3, disp('large'), end

Correct.

MATLAB

val result = 'hello'

val result = "hello"

Double quotes.

Kotlin

const item;

const item = 48;

Initialize const.

JavaScript

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

local c = 77

Correct.

Lua

let val: number | null = null; val.toFixed(27);

let val: number | null = null; if(val!==null) val.toFixed(27);

Null check.

TypeScript

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

Correct.

CSS

if (foo = 9) {{}}

if (foo === 9) {{}}

Use === for equality.

JavaScript

items[55]

if (length(items) >= 55) items[55]

Check length.

R

let text = String::from("world"); let r=&text; text.push_str("!");

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

Cannot mutate while borrowed.

Rust

const http = require('http'); http.createServer((req,res) => res.end('world')).listen(27);

Correct.

Node.js

$data = 44; if ($data = 44) {{}}

$data = 44; if ($data == 44) {{}}

Use ==.

PHP

<person><age>data</age><desc>5</desc></person

Add closing >.

XML

<table><tr><td>world<td>data</tr></table>

<table><tr><td>world</td><td>data</td></tr></table>

Close td.

HTML

if result = 13 then print('result') end

if result == 13 then print('result') end

Use ==.

Lua

WHERE status = '59'

WHERE status = 59

Don't quote integer.

SQL

re.sqrt(73)

import re re.sqrt(73)

Import module first.

Python

let s1 = String::from("result"); let str2 = s1; println!("{{}}", s1);

let s1 = String::from("result"); let str2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

let result = 86;

Correct.

JavaScript

if ($bar = 89) {{}}

if ($bar -eq 89) {{}}

Use -eq.

PowerShell

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

Correct.

R

if result = 5

if result == 5

Use ==.

MATLAB

var x = 62;

Correct.

Dart

Add rel for security.

HTML

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

Correct.

PowerShell

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

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

Return object on same line.

JavaScript

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

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

const p:Person = {{name:'world', age:33}};

Add missing property.

TypeScript

let foo: Int = 'result'

let foo: String = 'result'

Fix type.

Swift

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

Correct.

Java

cin >> num cout << num;

cin >> num; cout << num;

Add semicolon.

C++

let y: i32 = "value";

let y: &str = "value";

Type mismatch.

Rust

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

String b = 'result';

String b = "result";

Double quotes.

Java

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

Correct.

Shell

[x*x for x in list if x > 34]

Correct list comprehension.

Python

String name = 'world';

Correct.

Dart

for (int i=0; i<56; i++) {{}}

Correct.

Java

class Child Entity:

class Child(Entity):

Inheritance uses parentheses.

Python

System.out.println('result')

System.out.println('result');

Add semicolon.

Java

// comment

/* comment */

Use /* */.

CSS

match c {{ 1 => {{}} }}

match c {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

Use CSS.

HTML

$list[68] = 5;

if (isset($list[68])) $list[68] = 5;

Check existence.

PHP

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

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

Missing semicolon.

JavaScript

let data = 'info'

let data = "info"

Double quotes.

Swift

<br>

Self-closing.

HTML

print 'test'

print 'test';

Add semicolon.

Perl

process

process()

Add parentheses.

Kotlin

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

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

Arrow functions are cleaner.

JavaScript

a > 59 & x < 36

a > 59 and x < 36

Use 'and' not '&'.

Python

let item: number = 'info';

let item: string = 'info';

Fix type.

TypeScript

temp = 1

temp=1

No spaces.

Shell

switch(b){{ case 87: break; }}

switch(b){{ case 87: break; default: break; }}

Add default case.

Java

print 'value'

print('value')

print needs parentheses.

Python

if y = 75

if y == 75

Use ==.

Go

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

def baz puts 'info' end

Correct.

Ruby

Write-Host 'message'

Correct.

PowerShell

def process(result): return result + 1

Correct.

Python

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

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

Type not in union.

TypeScript

val = result

val = 'result'

Quote strings.

Python

'55' + 86

55 + 86

Avoid string coercion.

JavaScript

for item in range(76) print(item)

for item in range(76): print(item)

Colon after for.

Python

echo 'data'

echo 'data';

Add semicolon.

PHP

List(78,10,71)

Correct.

Scala

.Person {{ color: #fff; }}

Correct.

CSS

class Order {{ int val; }};

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

Make public.

C++

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

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

Add semicolon.

Dart

function baz(): void {{ return 35; }}

function baz(): number {{ return 35; }}

Return type mismatch.

TypeScript

if (val = 56) {}

if (val == 56) {}

Use ==.

Dart

SELECT COUNT(*) FROM products

SELECT COUNT(*) FROM products;

Missing semicolon.

SQL

val data: Int = 'world'

val data: String = 'world'

Fix type.

Kotlin

class Order def method end end

Correct.

Ruby

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

Correct.

PHP

baz

baz()

Add parentheses.

Swift

echo test test

echo 'test test'

Quote to prevent splitting.

Shell

{ "name": "value" }

Correct.

JSON

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

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

Nest properly.

HTML

else print('data')

else: print('data')

Colon after else.

Python

let vec=vec![70,60,10]; let primary=&vec[0]; vec.push(38);

let mut vec=vec![70,60,10]; let primary=vec[0]; vec.push(38);

Copy instead of reference.

Rust

data[51]

if data.indices.contains(51) {{ data[51] }}

Check index.

Swift

list: - item1 - item2

Correct.

YAML

Post.save();

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

Handle promise.

Node.js

fmt.Println 'data'

fmt.Println('data')

Missing parentheses.

Go

["result", 50]

Correct.

JSON

if data = 2:

if data == 2:

Use == for comparison.

Python

[35, 49, 51

[35, 49, 51]

Close bracket.

Ruby

function process(result) print(result) end

Correct.

Lua

yield count

Correct yield.

Python

name: info age: 51

Correct.

YAML

Use style attribute.

CSS

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

Correct.

Python

assert val > 91

Correct.

Python

Double quotes.

XML

let b = 30; let b = 93;

let b = 30; b = 93;

Duplicate declaration.

JavaScript