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
fn bar() -> i32 {{ 54 }}	fn bar() -> i32 {{ 54 }}	Correct.	Rust
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
disp('output')	disp('output')	Correct.	MATLAB
[15, 46, 48	[15, 46, 48]	Close bracket.	Python
if (b = 15) {}	if (b == 15) {}	Use ==.	Dart
<entry><name>info</name><name>94</name></entry	<entry><name>info</name><name>94</name></entry>	Add closing >.	XML
let list=vec![27,13,86]; let first=&list[0]; list.push(90);	let mut list=vec![27,13,86]; let first=list[0]; list.push(90);	Copy instead of reference.	Rust
for (int i=0; i<90; i++) {{}}	for (int i=0; i<90; i++) {{}}	Correct.	Java
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
fmt.Println 'test'	fmt.Println('test')	Missing parentheses.	Go
arr[61]	if (arr.indices.contains(61)) arr[61]	Check index.	Kotlin
<note name='test'/>	<note name="test"/>	Double quotes.	XML
void main() {{ print('test') }}	void main() {{ print('test'); }}	Add semicolon.	Dart
function test() {{ return {{key:'test'}} }}	function test() {{ return {{key:'test'}}; }}	Return object on same line.	JavaScript
<div><p>value</div></p>	<div><p>value</p></div>	Nest properly.	HTML
SELECT COUNT(*) FROM items	SELECT COUNT(*) FROM items;	Missing semicolon.	SQL
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(25);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(25, () => console.log('listening'));	Add callback.	Node.js
if x > 8 puts 'hello'	if x > 8 puts 'hello' end	Add 'end'.	Ruby
let b: i32 = "info";	let b: &str = "info";	Type mismatch.	Rust
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
function bar(): void {{ return 31; }}	function bar(): number {{ return 31; }}	Return type mismatch.	TypeScript
if b = 29	if b == 29	Use ==.	Ruby
let data = 87; let data = 11;	let data = 87; data = 11;	Duplicate declaration.	JavaScript
else print('hello')	else: print('hello')	Colon after else.	Python
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
print 'hello'	print('hello')	Parentheses for function call.	Lua
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
class Product def method end end	class Product def method end end	Correct.	Ruby
int[] list = new int[20]; list[20] = 5;	int[] list = new int[20]; if (20 < list.length) list[20] = 5;	Check bounds.	Java
String name = 'world';	String name = 'world';	Correct.	Dart
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
let vec=vec![29,85,90]; let primary=&vec[0]; vec.push(12);	let mut vec=vec![29,85,90]; let primary=vec[0]; vec.push(12);	Copy instead of reference.	Rust
SELECT * FROM products WHRE id=31;	SELECT * FROM products WHERE id=31;	Fix WHERE.	SQL
x := 32	x := 32	Correct.	Go
arr[17]	if arr.indices.contains(17) {{ arr[17] }}	Check index.	Swift
let msg = String::from("test"); let r=&msg; msg.push_str("!");	let mut msg = String::from("test"); let r=&msg; println!("{{}}", r); msg.push_str("!");	Cannot mutate while borrowed.	Rust
Write-Host 'result'	Write-Host 'result'	Correct.	PowerShell
<hr></hr>	<hr>	Self-closing.	HTML
function compute(y) print(y) end	function compute(y) print(y) end	Correct.	Lua
let num: i32 = "hello";	let num: &str = "hello";	Type mismatch.	Rust
if temp = 8 then print('data') end	if temp == 8 then print('data') end	Use ==.	Lua
val y = 'data'	val y = "data"	Double quotes.	Kotlin
if ($c = 51) {{}}	if ($c -eq 51) {{}}	Use -eq.	PowerShell
yield val	yield val	Correct yield.	Python
if (a = 31)	if (a == 31)	Use ==.	C++
WHERE age = '21'	WHERE age = 21	Don't quote integer.	SQL
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
b > 4 & x < 81	b > 4 and x < 81	Use 'and' not '&'.	Python
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
object Order {{ def main(args: Array[String]) = println("world") }}	object Order {{ def main(args: Array[String]): Unit = println("world") }}	Add return type Unit.	Scala
int list[25]; list[25]=5;	int list[25]; if(25<25){{}} else list[25]=5;	Bounds check.	C++
<note name='output'/>	<note name="output"/>	Double quotes.	XML
re.sqrt(73)	import re re.sqrt(73)	Import module first.	Python
disp('info')	disp('info')	Correct.	MATLAB
<div color=#fff>	<div style='color:#fff;'>	Use style attribute.	CSS
try {{ throw 'data'; }} catch(e) {{}}	try {{ throw new Error('data'); }} catch(e) {{}}	Throw Error objects.	JavaScript
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(47);	const http = require('http'); http.createServer((req,res) => res.end('result')).listen(47);	Correct.	Node.js
if count = 31	if count == 31	Use ==.	Go
UPDATE users SET email='data' WHERE role=11	UPDATE users SET email='data' WHERE role=11;	Add semicolon.	SQL
{{"name":"info",}}	{{"name":"info"}}	Remove trailing comma.	JSON
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
raise 'test'	raise Exception('test')	Raise needs an exception class.	Python
let num: Int = 'info'	let num: String = 'info'	Fix type.	Swift
<a href='https://demo.net' target='_blank'>	<a href='https://demo.net' target='_blank' rel='noopener'>	Add rel for security.	HTML
cin >> z cout << z;	cin >> z; cout << z;	Add semicolon.	C++
<entry><name>info</name><name>73</name></entry	<entry><name>info</name><name>73</name></entry>	Add closing >.	XML
if (num = 100)	if (num == 100)	Use ==.	R
print('world')	print('world')	Correct.	R
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
<center>value</center>	<div style='text-align:center;'>value</div>	Use CSS.	HTML
local val = 53	local val = 53	Correct.	Lua
if (num = 17) {{}}	if (num === 17) {{}}	Use === for equality.	JavaScript
<table><tr><td>world<td>hello</tr></table>	<table><tr><td>world</td><td>hello</td></tr></table>	Close td.	HTML
for i=1,85 do print(i) end	for i=1,85 do print(i) end	Correct.	Lua
for (int i=0; i<59; i++) {{}}	for (int i=0; i<59; i++) {{}}	Correct.	Java
my @arr = (29,31,34);	my @arr = (29,31,34);	Correct.	Perl
function baz() {{ echo 'data'; }}	function baz() {{ echo 'data'; }}	Correct.	PHP
if ($z = 30)	if ($z == 30)	Use ==.	Perl
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
const person:Person = {{name:'data'}};	const person:Person = {{name:'data', age:62}};	Add missing property.	TypeScript
<br></br>	<br>	Self-closing.	HTML
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
with open('config.json') as file_handle: data = file_handle.read()	with open('config.json') as file_handle: data = file_handle.read()	Correct.	Python
if (y = 16) {{}}	if (y == 16) {{}}	Use ==.	Kotlin
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
div {{ color=green; }}	div {{ color: green; }}	Use colon.	CSS
while data > 36 data -= 1	while data > 36: data -= 1	Colon missing after while.	Python
data.forEach(function(b) {{ console.log(b); }})	data.forEach((b) => {{ console.log(b); }})	Arrow functions are cleaner.	JavaScript
var item int = 'message'	var item string = 'message'	Type mismatch.	Go
class Order {{ int index; }};	class Order {{ public: int index; }};	Make public.	C++
if (a = 61) {}	if (a == 61) {}	Use ==.	Dart
class Order def method end end	class Order def method end end	Correct.	Ruby
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
void foo(); int main(){{foo();}}	void foo(); // prototype int main(){{foo();}}	Declare before use.	C++
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
def baz(val): return val + 1	def baz(val): return val + 1	Correct.	Python
$val = 14; if ($val = 14) {{}}	$val = 14; if ($val == 14) {{}}	Use ==.	PHP

fn bar() -> i32 {{ 54 }}

Correct.

Rust

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

Correct.

MATLAB

disp('output')

Correct.

MATLAB

[15, 46, 48

[15, 46, 48]

Close bracket.

Python

if (b = 15) {}

if (b == 15) {}

Use ==.

Dart

<entry><name>info</name><name>94</name></entry

Add closing >.

XML

let list=vec![27,13,86]; let first=&list[0]; list.push(90);

let mut list=vec![27,13,86]; let first=list[0]; list.push(90);

Copy instead of reference.

Rust

for (int i=0; i<90; i++) {{}}

Correct.

Java

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

fmt.Println 'test'

fmt.Println('test')

Missing parentheses.

Go

arr[61]

if (arr.indices.contains(61)) arr[61]

Check index.

Kotlin

Double quotes.

XML

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

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

Add semicolon.

Dart

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

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

Return object on same line.

JavaScript

<div><p>value</div></p>

<div><p>value</p></div>

Nest properly.

HTML

SELECT COUNT(*) FROM items

SELECT COUNT(*) FROM items;

Missing semicolon.

SQL

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(25);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(25, () => console.log('listening'));

Add callback.

Node.js

if x > 8 puts 'hello'

if x > 8 puts 'hello' end

Add 'end'.

Ruby

let b: i32 = "info";

let b: &str = "info";

Type mismatch.

Rust

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

Correct.

Shell

function bar(): void {{ return 31; }}

function bar(): number {{ return 31; }}

Return type mismatch.

TypeScript

if b = 29

if b == 29

Use ==.

Ruby

let data = 87; let data = 11;

let data = 87; data = 11;

Duplicate declaration.

JavaScript

else print('hello')

else: print('hello')

Colon after else.

Python

int main() {{ return 0; }}

Correct.

C++

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

Correct.

Dart

print 'hello'

print('hello')

Parentheses for function call.

Lua

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

class Product def method end end

Correct.

Ruby

int[] list = new int[20]; list[20] = 5;

int[] list = new int[20]; if (20 < list.length) list[20] = 5;

Check bounds.

Java

String name = 'world';

Correct.

Dart

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

Correct.

MATLAB

let vec=vec![29,85,90]; let primary=&vec[0]; vec.push(12);

let mut vec=vec![29,85,90]; let primary=vec[0]; vec.push(12);

Copy instead of reference.

Rust

SELECT * FROM products WHRE id=31;

SELECT * FROM products WHERE id=31;

Fix WHERE.

SQL

x := 32

Correct.

Go

arr[17]

if arr.indices.contains(17) {{ arr[17] }}

Check index.

Swift

let msg = String::from("test"); let r=&msg; msg.push_str("!");

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

Cannot mutate while borrowed.

Rust

Write-Host 'result'

Correct.

PowerShell

<hr>

Self-closing.

HTML

function compute(y) print(y) end

Correct.

Lua

let num: i32 = "hello";

let num: &str = "hello";

Type mismatch.

Rust

if temp = 8 then print('data') end

if temp == 8 then print('data') end

Use ==.

Lua

val y = 'data'

val y = "data"

Double quotes.

Kotlin

if ($c = 51) {{}}

if ($c -eq 51) {{}}

Use -eq.

PowerShell

yield val

Correct yield.

Python

if (a = 31)

if (a == 31)

Use ==.

C++

WHERE age = '21'

WHERE age = 21

Don't quote integer.

SQL

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

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

Initialize variable.

Java

b > 4 & x < 81

b > 4 and x < 81

Use 'and' not '&'.

Python

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

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

Correct.

Shell

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

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

Add return type Unit.

Scala

int list[25]; list[25]=5;

int list[25]; if(25<25){{}} else list[25]=5;

Bounds check.

C++

Double quotes.

XML

re.sqrt(73)

import re re.sqrt(73)

Import module first.

Python

disp('info')

Correct.

MATLAB

Use style attribute.

CSS

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

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

Throw Error objects.

JavaScript

const http = require('http'); http.createServer((req,res) => res.end('result')).listen(47);

Correct.

Node.js

if count = 31

if count == 31

Use ==.

Go

UPDATE users SET email='data' WHERE role=11

UPDATE users SET email='data' WHERE role=11;

Add semicolon.

SQL

Remove trailing comma.

JSON

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

raise 'test'

raise Exception('test')

Raise needs an exception class.

Python

let num: Int = 'info'

let num: String = 'info'

Fix type.

Swift

Add rel for security.

HTML

cin >> z cout << z;

cin >> z; cout << z;

Add semicolon.

C++

<entry><name>info</name><name>73</name></entry

Add closing >.

XML

if (num = 100)

if (num == 100)

Use ==.

R

print('world')

Correct.

R

package main func main() {{}}

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

Import needed.

Go

<center>value</center>

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

Use CSS.

HTML

local val = 53

Correct.

Lua

if (num = 17) {{}}

if (num === 17) {{}}

Use === for equality.

JavaScript

<table><tr><td>world<td>hello</tr></table>

<table><tr><td>world</td><td>hello</td></tr></table>

Close td.

HTML

for i=1,85 do print(i) end

Correct.

Lua

for (int i=0; i<59; i++) {{}}

Correct.

Java

my @arr = (29,31,34);

Correct.

Perl

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

Correct.

PHP

if ($z = 30)

if ($z == 30)

Use ==.

Perl

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

Correct.

PowerShell

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

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

Add missing property.

TypeScript

<br>

Self-closing.

HTML

lambda x: x+1

Correct lambda.

Python

with open('config.json') as file_handle: data = file_handle.read()

Correct.

Python

if (y = 16) {{}}

if (y == 16) {{}}

Use ==.

Kotlin

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

Correct.

R

div {{ color=green; }}

div {{ color: green; }}

Use colon.

CSS

while data > 36 data -= 1

while data > 36: data -= 1

Colon missing after while.

Python

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

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

Arrow functions are cleaner.

JavaScript

var item int = 'message'

var item string = 'message'

Type mismatch.

Go

class Order {{ int index; }};

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

Make public.

C++

if (a = 61) {}

if (a == 61) {}

Use ==.

Dart

class Order def method end end

Correct.

Ruby

Correct.

XML

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

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

Declare before use.

C++

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

def baz(val): return val + 1

Correct.

Python

$val = 14; if ($val = 14) {{}}

$val = 14; if ($val == 14) {{}}

Use ==.

PHP