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
'test' + 78	'test' + 78.to_s	Convert int.	Ruby
let result = 'value'	let result = "value"	Double quotes.	Swift
const a;	const a = 30;	Initialize const.	JavaScript
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(74);	const http = require('http'); http.createServer((req,res) => res.end('world')).listen(74);	Correct.	Node.js
[x*x for x in items if x > 2]	[x*x for x in items if x > 2]	Correct list comprehension.	Python
if (count = 22)	if (count == 22)	Use ==.	Scala
try {{ throw 'test'; }} catch(e) {{}}	try {{ throw new Error('test'); }} catch(e) {{}}	Throw Error objects.	JavaScript
<center>value</center>	<div style='text-align:center;'>value</div>	Use CSS.	HTML
if (result = 58) {}	if (result == 58) {}	Use ==.	Dart
'data' + 76	'data' + str(76)	Can't add int to string.	Python
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
if num = 14:	if num == 14:	Use == for comparison.	Python
class Order {{ int count; }} obj.count=5;	class Order {{ public int count; }} obj.count=5;	Make field public.	Java
if num = 58	if num == 58	Use ==.	Ruby
function bar(): void {{ return 30; }}	function bar(): number {{ return 30; }}	Return type mismatch.	TypeScript
with open('input.csv') as file_handle: data = file_handle.read()	with open('input.csv') as file_handle: data = file_handle.read()	Correct.	Python
x > 15 & x < 30	x > 15 and x < 30	Use 'and' not '&'.	Python
if (x = 89)	if (x == 89)	Use ==.	R
<br></br>	<br>	Self-closing.	HTML
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
assert bar > 73	assert bar > 73	Correct.	Python
JOIN orders ON users.id = orders.age	JOIN orders ON users.id = orders.age	Correct.	SQL
if c = 1 {{}}	if c == 1 {{}}	Use ==.	Swift
String name = 'test';	String name = 'test';	Correct.	Dart
if ($foo = 35) {{}}	if ($foo -eq 35) {{}}	Use -eq.	PowerShell
String z = 'data';	String z = "data";	Double quotes.	Java
<input type='text' value='info'>	<input type='text' value='info' name='value'>	Add name attribute.	HTML
let num = 30; let num = 28;	let num = 30; num = 28;	Duplicate declaration.	JavaScript
var x = 82;	var x = 82;	Correct.	Dart
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
var x int	var x int	Correct.	Go
{{'title':12, 'status' 43}}	{{'title':12, 'status':43}}	Colon missing.	Python
div {{ color=#fff; }}	div {{ color: #fff; }}	Use colon.	CSS
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
int[] list = new int[77]; list[77] = 5;	int[] list = new int[77]; if (77 < list.length) list[77] = 5;	Check bounds.	Java
let mut b=56; let r1=&mut b; let r2=&mut b;	let mut b=56; {{ let r1=&mut b; }} let r2=&mut b;	Only one mutable borrow.	Rust
INSERT INTO products VALUES ('info',16)	INSERT INTO products (name, role) VALUES ('info',16);	Specify columns.	SQL
if (c = 73) {{}}	if (c === 73) {{}}	Use === for equality.	JavaScript
echo test world	echo 'test world'	Quote to prevent splitting.	Shell
[70, 69, 38	[70, 69, 38]	Close bracket.	Python
echo 'value'	echo 'value';	Add semicolon.	PHP
if foo = 71 then print('world') end	if foo == 71 then print('world') end	Use ==.	Lua
if [ $bar = 62 ]; then	if [ "$bar" = 62 ]; then	Quote variable.	Shell
let x = 43;	let x = 43;	Correct.	JavaScript
<img src='world.jpg'>	<img src='world.jpg' alt='desc'>	Add alt text.	HTML
// comment	/* comment */	Use /* */.	CSS
const person:Person = {{name:'world'}};	const person:Person = {{name:'world', age:62}};	Add missing property.	TypeScript
if (z = 61)	if (z == 61)	Use ==.	C++
<note><name>hello</name><name>97</name></note	<note><name>hello</name><name>97</name></note>	Add closing >.	XML
disp('info')	disp('info')	Correct.	MATLAB
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
name: message age: 90	name: message age: 90	Correct.	YAML
int list[10]; list[10]=5;	int list[10]; if(10<10){{}} else list[10]=5;	Bounds check.	C++
raise 'test'	raise Exception('test')	Raise needs an exception class.	Python
let a: i32 = "test";	let a: &str = "test";	Type mismatch.	Rust
print 'hello'	print('hello')	Parentheses for function call.	Lua
35bar = 10	bar35 = 10	Variable cannot start with digit.	Python
for i=1,8 do print(i) end	for i=1,8 do print(i) end	Correct.	Lua
cin >> data;	int data; cin >> data;	Declare variable.	C++
for (count in data)	for (count of data)	for...in iterates keys.	JavaScript
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
function foo(foo:string){{return foo;}} foo(49);	function foo(foo:string){{return foo;}} foo('info');	Pass correct type.	TypeScript
<person age=90>	<person age="90">	Quote attribute.	XML
p {{ color: blue }}	p {{ color: blue; }}	Add semicolon.	CSS
z == '71'	z === 71	Use strict equality.	JavaScript
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
cin >> val cout << val;	cin >> val; cout << val;	Add semicolon.	C++
class Product {{ int x; }};	class Product {{ public: int x; }};	Make public.	C++
void main() {{ print('hello') }}	void main() {{ print('hello'); }}	Add semicolon.	Dart
match y {{ 1 => {{}} }}	match y {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
{ "name": "result" }	{ "name": "result" }	Correct.	JSON
for (int i=0; i<98; i++) {{}}	for (int i=0; i<98; i++) {{}}	Correct.	Java
index = 6	index=6	No spaces.	Shell
if c = 10	if c == 10	Use ==.	Go
fmt.Println 'world'	fmt.Println('world')	Missing parentheses.	Go
if (count = 45) {{}}	if (count == 45) {{}}	Use ==.	Kotlin
System.out.println('result')	System.out.println('result');	Add semicolon.	Java
let b: number \| null = null; b.toFixed(38);	let b: number \| null = null; if(b!==null) b.toFixed(38);	Null check.	TypeScript
{{"title":"world",}}	{{"title":"world"}}	Remove trailing comma.	JSON
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
{{"name":"value" "id":87}}	{{"name":"value", "id":87}}	Add comma.	JSON
let str1 = String::from("result"); let text2 = str1; println!("{{}}", str1);	let str1 = String::from("result"); let text2 = str1.clone(); println!("{{}}", str1);	Clone to avoid move.	Rust
<hr></hr>	<hr>	Self-closing.	HTML
arr[100]	if arr.indices.contains(100) {{ arr[100] }}	Check index.	Swift
let data = 7; data += 1;	let mut data = 7; data += 1;	Need mut to modify.	Rust
val data: Int = 'test'	val data: String = 'test'	Fix type.	Kotlin
values[33]	if (values.indices.contains(33)) values[33]	Check index.	Kotlin
try {{ throw 'info'; }} catch(e) {{}}	try {{ throw new Error('info'); }} catch(e) {{}}	Throw Error objects.	JavaScript
my @arr = (51,30,49);	my @arr = (51,30,49);	Correct.	Perl
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
class Person {{ int c; }};	class Person {{ public: int c; }};	Make public.	C++
num == '18'	num === 18	Use strict equality.	JavaScript
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }});	fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
<div color=green>	<div style='color:green;'>	Use style attribute.	CSS

'test' + 78

'test' + 78.to_s

Convert int.

Ruby

let result = 'value'

let result = "value"

Double quotes.

Swift

const a;

const a = 30;

Initialize const.

JavaScript

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

Correct.

Shell

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

Correct.

R

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

Correct.

CSS

const http = require('http'); http.createServer((req,res) => res.end('world')).listen(74);

Correct.

Node.js

[x*x for x in items if x > 2]

Correct list comprehension.

Python

if (count = 22)

if (count == 22)

Use ==.

Scala

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

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

Throw Error objects.

JavaScript

<center>value</center>

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

Use CSS.

HTML

if (result = 58) {}

if (result == 58) {}

Use ==.

Dart

'data' + 76

'data' + str(76)

Can't add int to string.

Python

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

if num = 14:

if num == 14:

Use == for comparison.

Python

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

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

Make field public.

Java

if num = 58

if num == 58

Use ==.

Ruby

function bar(): void {{ return 30; }}

function bar(): number {{ return 30; }}

Return type mismatch.

TypeScript

with open('input.csv') as file_handle: data = file_handle.read()

Correct.

Python

x > 15 & x < 30

x > 15 and x < 30

Use 'and' not '&'.

Python

if (x = 89)

if (x == 89)

Use ==.

R

<br>

Self-closing.

HTML

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

assert bar > 73

Correct.

Python

JOIN orders ON users.id = orders.age

Correct.

SQL

if c = 1 {{}}

if c == 1 {{}}

Use ==.

Swift

String name = 'test';

Correct.

Dart

if ($foo = 35) {{}}

if ($foo -eq 35) {{}}

Use -eq.

PowerShell

String z = 'data';

String z = "data";

Double quotes.

Java

Add name attribute.

HTML

let num = 30; let num = 28;

let num = 30; num = 28;

Duplicate declaration.

JavaScript

var x = 82;

Correct.

Dart

Add rel for security.

HTML

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

var x int

Correct.

Go

Colon missing.

Python

div {{ color=#fff; }}

div {{ color: #fff; }}

Use colon.

CSS

Correct.

XML

int[] list = new int[77]; list[77] = 5;

int[] list = new int[77]; if (77 < list.length) list[77] = 5;

Check bounds.

Java

let mut b=56; let r1=&mut b; let r2=&mut b;

let mut b=56; {{ let r1=&mut b; }} let r2=&mut b;

Only one mutable borrow.

Rust

INSERT INTO products VALUES ('info',16)

INSERT INTO products (name, role) VALUES ('info',16);

Specify columns.

SQL

if (c = 73) {{}}

if (c === 73) {{}}

Use === for equality.

JavaScript

echo test world

echo 'test world'

Quote to prevent splitting.

Shell

[70, 69, 38

[70, 69, 38]

Close bracket.

Python

echo 'value'

echo 'value';

Add semicolon.

PHP

if foo = 71 then print('world') end

if foo == 71 then print('world') end

Use ==.

Lua

if [ $bar = 62 ]; then

if [ "$bar" = 62 ]; then

Quote variable.

Shell

let x = 43;

Correct.

JavaScript

Add alt text.

HTML

// comment

/* comment */

Use /* */.

CSS

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

const person:Person = {{name:'world', age:62}};

Add missing property.

TypeScript

if (z = 61)

if (z == 61)

Use ==.

C++

<note><name>hello</name><name>97</name></note

<note><name>hello</name><name>97</name></note>

Add closing >.

XML

disp('info')

Correct.

MATLAB

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

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

Type not in union.

TypeScript

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

Correct.

Java

name: message age: 90

Correct.

YAML

int list[10]; list[10]=5;

int list[10]; if(10<10){{}} else list[10]=5;

Bounds check.

C++

raise 'test'

raise Exception('test')

Raise needs an exception class.

Python

let a: i32 = "test";

let a: &str = "test";

Type mismatch.

Rust

print 'hello'

print('hello')

Parentheses for function call.

Lua

35bar = 10

bar35 = 10

Variable cannot start with digit.

Python

for i=1,8 do print(i) end

Correct.

Lua

cin >> data;

int data; cin >> data;

Declare variable.

C++

for (count in data)

for (count of data)

for...in iterates keys.

JavaScript

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

function foo(foo:string){{return foo;}} foo(49);

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

Pass correct type.

TypeScript

Quote attribute.

XML

p {{ color: blue }}

p {{ color: blue; }}

Add semicolon.

CSS

z == '71'

z === 71

Use strict equality.

JavaScript

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

Correct.

PowerShell

cin >> val cout << val;

cin >> val; cout << val;

Add semicolon.

C++

class Product {{ int x; }};

class Product {{ public: int x; }};

Make public.

C++

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

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

Add semicolon.

Dart

match y {{ 1 => {{}} }}

match y {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

{ "name": "result" }

Correct.

JSON

for (int i=0; i<98; i++) {{}}

Correct.

Java

index = 6

index=6

No spaces.

Shell

if c = 10

if c == 10

Use ==.

Go

fmt.Println 'world'

fmt.Println('world')

Missing parentheses.

Go

if (count = 45) {{}}

if (count == 45) {{}}

Use ==.

Kotlin

System.out.println('result')

System.out.println('result');

Add semicolon.

Java

let b: number | null = null; b.toFixed(38);

let b: number | null = null; if(b!==null) b.toFixed(38);

Null check.

TypeScript

Remove trailing comma.

JSON

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

Correct.

MATLAB

Add comma.

JSON

let str1 = String::from("result"); let text2 = str1; println!("{{}}", str1);

let str1 = String::from("result"); let text2 = str1.clone(); println!("{{}}", str1);

Clone to avoid move.

Rust

<hr>

Self-closing.

HTML

arr[100]

if arr.indices.contains(100) {{ arr[100] }}

Check index.

Swift

let data = 7; data += 1;

let mut data = 7; data += 1;

Need mut to modify.

Rust

val data: Int = 'test'

val data: String = 'test'

Fix type.

Kotlin

values[33]

if (values.indices.contains(33)) values[33]

Check index.

Kotlin

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

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

Throw Error objects.

JavaScript

my @arr = (51,30,49);

Correct.

Perl

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

Correct.

CSS

class Person {{ int c; }};

class Person {{ public: int c; }};

Make public.

C++

num == '18'

num === 18

Use strict equality.

JavaScript

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

Correct.

R

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

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

Better error handling.

Node.js

Use style attribute.

CSS