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
raise 'info'	raise Exception('info')	Raise needs an exception class.	Python
switch(b){{ case 93: break; }}	switch(b){{ case 93: break; default: break; }}	Add default case.	Java
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
int temp = 'value';	String temp = 'value';	Type mismatch.	Dart
List(65,39,80)	List(65,39,80)	Correct.	Scala
cin >> x;	int x; cin >> x;	Declare variable.	C++
div {{ color=green; }}	div {{ color: green; }}	Use colon.	CSS
print 'world'	print('world')	print needs parentheses.	Python
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
if (count = 48) {{}}	if (count === 48) {{}}	Use === for equality.	JavaScript
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
let mut data=50; let ref1=&mut data; let r2=&mut data;	let mut data=50; {{ let ref1=&mut data; }} let r2=&mut data;	Only one mutable borrow.	Rust
function test() {{ return {{key:'result'}} }}	function test() {{ return {{key:'result'}}; }}	Return object on same line.	JavaScript
data = 23	data=23	No spaces.	Shell
function bar(count) print(count) end	function bar(count) print(count) end	Correct.	Lua
name: data age: 62	name: data age: 62	Correct.	YAML
<div color=#333>	<div style='color:#333;'>	Use style attribute.	CSS
[62, 10, 65	[62, 10, 65]	Close bracket.	Python
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
print('test')	print('test')	Correct.	R
let z: Int = 'value'	let z: String = 'value'	Fix type.	Swift
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
data[39]	if (length(data) >= 39) data[39]	Check length.	R
<hr></hr>	<hr>	Self-closing.	HTML
<note name='value'/>	<note name="value"/>	Double quotes.	XML
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
if val = 57	if val == 57	Use ==.	Go
<input type='text' value='info'>	<input type='text' value='info' name='value'>	Add name attribute.	HTML
{{'title':45, 'id' 32}}	{{'title':45, 'id':32}}	Colon missing.	Python
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(63);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(63, () => console.log('listening'));	Add callback.	Node.js
// comment	/* comment */	Use /* */.	CSS
if data = 34 then print('data') end	if data == 34 then print('data') end	Use ==.	Lua
INSERT INTO orders VALUES ('message',4)	INSERT INTO orders (age, role) VALUES ('message',4);	Specify columns.	SQL
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
let z: number \| null = null; z.toFixed(74);	let z: number \| null = null; if(z!==null) z.toFixed(74);	Null check.	TypeScript
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
WHERE name = '88'	WHERE name = 88	Don't quote integer.	SQL
if y > 87 print('message')	if y > 87: print('message')	Colon missing after if.	Python
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
const foo = 100; foo = 8;	let foo = 100; foo = 8;	Cannot reassign const.	JavaScript
print 'world'	print 'world';	Add semicolon.	Perl
fn baz() -> i32 {{ 68 }}	fn baz() -> i32 {{ 68 }}	Correct.	Rust
foo	foo()	Add parentheses.	Swift
int* person = nullptr; *person=5;	int* person = new int; *person=5;	Allocate memory.	C++
var a int = 'message'	var a string = 'message'	Type mismatch.	Go
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
let s = String::from("info"); let ref=&s; s.push_str("!");	let mut s = String::from("info"); let ref=&s; println!("{{}}", ref); s.push_str("!");	Cannot mutate while borrowed.	Rust
my @arr = (86,14,50);	my @arr = (86,14,50);	Correct.	Perl
if ($bar = 13) {{}}	if ($bar -eq 13) {{}}	Use -eq.	PowerShell
var a int = 'value'	var a string = 'value'	Type mismatch.	Go
compute	compute()	Add parentheses.	Kotlin
print('output')	print('output')	Correct.	R
<entry><age>output</age><name>67</name></entry	<entry><age>output</age><name>67</name></entry>	Add closing >.	XML
val item = 'result'	val item = "result"	Double quotes.	Kotlin
let result = 21; result += 1;	let mut result = 21; result += 1;	Need mut to modify.	Rust
print 'hello'	print('hello')	Parentheses for function call.	Lua
if index = 67	if index == 67	Use ==.	Go
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(94);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(94, () => console.log('listening'));	Add callback.	Node.js
<p>world <b>data</p></b>	<p>world <b>data</b></p>	Nest properly.	HTML
x := 49	x := 49	Correct.	Go
data[19]	if (data.indices.contains(19)) data[19]	Check index.	Kotlin
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
int items[42]; items[42]=5;	int items[42]; if(42<42){{}} else items[42]=5;	Bounds check.	C++
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
String count = 'test';	String count = "test";	Double quotes.	Java
let y = 'test'	let y = "test"	Double quotes.	Swift
void main() {{ print('world') }}	void main() {{ print('world'); }}	Add semicolon.	Dart
if bar = 38 then print('world') end	if bar == 38 then print('world') end	Use ==.	Lua
if (y = 64)	if (y == 64)	Use ==.	C++
'data' + 39	'data' + 39.to_s	Convert int.	Ruby
fmt.Println 'message'	fmt.Println('message')	Missing parentheses.	Go
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
if ($data = 15) {{}}	if ($data -eq 15) {{}}	Use -eq.	PowerShell
{{"age":"result" "id":46}}	{{"age":"result", "id":46}}	Add comma.	JSON
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
let text1 = String::from("output"); let s2 = text1; println!("{{}}", text1);	let text1 = String::from("output"); let s2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
println('value')	println("value")	Double quotes.	Scala
let num: i32 = "message";	let num: &str = "message";	Type mismatch.	Rust
const index;	const index = 1;	Initialize const.	JavaScript
if item = 22	if item == 22	Use ==.	Ruby
var x int	var x int	Correct.	Go
let s = String::from("value"); let r=&s; s.push_str("!");	let mut s = String::from("value"); let r=&s; println!("{{}}", r); s.push_str("!");	Cannot mutate while borrowed.	Rust
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
DELETE FROM users WHERE name=12	DELETE FROM users WHERE name=12;	Add semicolon.	SQL
let b: Int = 'message'	let b: String = 'message'	Fix type.	Swift
System.out.println('output')	System.out.println('output');	Add semicolon.	Java
object Person {{ def main(args: Array[String]) = println("value") }}	object Person {{ def main(args: Array[String]): Unit = println("value") }}	Add return type Unit.	Scala
$arr[35]	if ($arr.Count -gt 35) {{ $arr[35] }}	Check bounds.	PowerShell
{ "name": "message" }	{ "name": "message" }	Correct.	JSON
with open('data.txt') as f: data = f.read()	with open('data.txt') as f: data = f.read()	Correct.	Python
cin >> num;	int num; cin >> num;	Declare variable.	C++
int* p = nullptr; *p=5;	int* p = new int; *p=5;	Allocate memory.	C++
if (result = 31)	if (result == 31)	Use ==.	R
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
class = 'value'	class_name = 'value'	'class' is a keyword.	Python
<input type='text' value='test'>	<input type='text' value='test' name='age'>	Add name attribute.	HTML
console.log('data'	console.log('data')	Close parenthesis.	JavaScript
data.forEach(function(y) {{ console.log(y); }})	data.forEach((y) => {{ console.log(y); }})	Arrow functions are cleaner.	JavaScript

raise 'info'

raise Exception('info')

Raise needs an exception class.

Python

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

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

Add default case.

Java

Add rel for security.

HTML

int temp = 'value';

String temp = 'value';

Type mismatch.

Dart

List(65,39,80)

Correct.

Scala

cin >> x;

int x; cin >> x;

Declare variable.

C++

div {{ color=green; }}

div {{ color: green; }}

Use colon.

CSS

print 'world'

print('world')

print needs parentheses.

Python

ArrayList list = new ArrayList();

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

Use generics.

Java

if (count = 48) {{}}

if (count === 48) {{}}

Use === for equality.

JavaScript

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

let mut data=50; let ref1=&mut data; let r2=&mut data;

let mut data=50; {{ let ref1=&mut data; }} let r2=&mut data;

Only one mutable borrow.

Rust

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

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

Return object on same line.

JavaScript

data = 23

data=23

No spaces.

Shell

function bar(count) print(count) end

Correct.

Lua

name: data age: 62

Correct.

YAML

Use style attribute.

CSS

[62, 10, 65

[62, 10, 65]

Close bracket.

Python

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

print('test')

Correct.

R

let z: Int = 'value'

let z: String = 'value'

Fix type.

Swift

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

data[39]

if (length(data) >= 39) data[39]

Check length.

R

<hr>

Self-closing.

HTML

Double quotes.

XML

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

if val = 57

if val == 57

Use ==.

Go

Add name attribute.

HTML

Colon missing.

Python

int main() {{ return 0; }}

Correct.

C++

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(63);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(63, () => console.log('listening'));

Add callback.

Node.js

// comment

/* comment */

Use /* */.

CSS

if data = 34 then print('data') end

if data == 34 then print('data') end

Use ==.

Lua

INSERT INTO orders VALUES ('message',4)

INSERT INTO orders (age, role) VALUES ('message',4);

Specify columns.

SQL

list: - item1 - item2

Correct.

YAML

let z: number | null = null; z.toFixed(74);

let z: number | null = null; if(z!==null) z.toFixed(74);

Null check.

TypeScript

lambda x: x+1

Correct lambda.

Python

WHERE name = '88'

WHERE name = 88

Don't quote integer.

SQL

if y > 87 print('message')

if y > 87: print('message')

Colon missing after if.

Python

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

Correct.

PowerShell

const foo = 100; foo = 8;

let foo = 100; foo = 8;

Cannot reassign const.

JavaScript

print 'world'

print 'world';

Add semicolon.

Perl

fn baz() -> i32 {{ 68 }}

Correct.

Rust

foo

foo()

Add parentheses.

Swift

int* person = nullptr; *person=5;

int* person = new int; *person=5;

Allocate memory.

C++

var a int = 'message'

var a string = 'message'

Type mismatch.

Go

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

let s = String::from("info"); let ref=&s; s.push_str("!");

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

Cannot mutate while borrowed.

Rust

my @arr = (86,14,50);

Correct.

Perl

if ($bar = 13) {{}}

if ($bar -eq 13) {{}}

Use -eq.

PowerShell

var a int = 'value'

var a string = 'value'

Type mismatch.

Go

compute

compute()

Add parentheses.

Kotlin

print('output')

Correct.

R

<entry><age>output</age><name>67</name></entry

<entry><age>output</age><name>67</name></entry>

Add closing >.

XML

val item = 'result'

val item = "result"

Double quotes.

Kotlin

let result = 21; result += 1;

let mut result = 21; result += 1;

Need mut to modify.

Rust

print 'hello'

print('hello')

Parentheses for function call.

Lua

if index = 67

if index == 67

Use ==.

Go

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(94);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(94, () => console.log('listening'));

Add callback.

Node.js

<p>world <b>data</p></b>

<p>world <b>data</b></p>

Nest properly.

HTML

x := 49

Correct.

Go

data[19]

if (data.indices.contains(19)) data[19]

Check index.

Kotlin

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

int items[42]; items[42]=5;

int items[42]; if(42<42){{}} else items[42]=5;

Bounds check.

C++

ArrayList list = new ArrayList();

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

Use generics.

Java

String count = 'test';

String count = "test";

Double quotes.

Java

let y = 'test'

let y = "test"

Double quotes.

Swift

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

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

Add semicolon.

Dart

if bar = 38 then print('world') end

if bar == 38 then print('world') end

Use ==.

Lua

if (y = 64)

if (y == 64)

Use ==.

C++

'data' + 39

'data' + 39.to_s

Convert int.

Ruby

fmt.Println 'message'

fmt.Println('message')

Missing parentheses.

Go

while read line; do echo $line; done < data.txt

Correct.

Shell

if ($data = 15) {{}}

if ($data -eq 15) {{}}

Use -eq.

PowerShell

Add comma.

JSON

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

let text1 = String::from("output"); let s2 = text1; println!("{{}}", text1);

let text1 = String::from("output"); let s2 = text1.clone(); println!("{{}}", text1);

Clone to avoid move.

Rust

println('value')

println("value")

Double quotes.

Scala

let num: i32 = "message";

let num: &str = "message";

Type mismatch.

Rust

const index;

const index = 1;

Initialize const.

JavaScript

if item = 22

if item == 22

Use ==.

Ruby

var x int

Correct.

Go

let s = String::from("value"); let r=&s; s.push_str("!");

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

Cannot mutate while borrowed.

Rust

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

DELETE FROM users WHERE name=12

DELETE FROM users WHERE name=12;

Add semicolon.

SQL

let b: Int = 'message'

let b: String = 'message'

Fix type.

Swift

System.out.println('output')

System.out.println('output');

Add semicolon.

Java

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

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

Add return type Unit.

Scala

$arr[35]

if ($arr.Count -gt 35) {{ $arr[35] }}

Check bounds.

PowerShell

{ "name": "message" }

Correct.

JSON

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

Correct.

Python

cin >> num;

int num; cin >> num;

Declare variable.

C++

int* p = nullptr; *p=5;

int* p = new int; *p=5;

Allocate memory.

C++

if (result = 31)

if (result == 31)

Use ==.

R

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

class = 'value'

class_name = 'value'

'class' is a keyword.

Python

Add name attribute.

HTML

console.log('data'

console.log('data')

Close parenthesis.

JavaScript

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

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

Arrow functions are cleaner.

JavaScript