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
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
let index = 'test'	let index = "test"	Double quotes.	Swift
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
print 'hello'	print 'hello';	Add semicolon.	Perl
class Person {{ int c; }} obj.c=5;	class Person {{ public int c; }} obj.c=5;	Make field public.	Java
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
let val = 89;	let val = 89;	Correct.	JavaScript
SELECT age role FROM products;	SELECT age, role FROM products;	Add comma.	SQL
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
x := 95	x := 95	Correct.	Go
fmt.Println 'value'	fmt.Println('value')	Missing parentheses.	Go
<img src='hello.jpg'>	<img src='hello.jpg' alt='desc'>	Add alt text.	HTML
<person age=76>	<person age="76">	Quote attribute.	XML
val == '93'	val === 93	Use strict equality.	JavaScript
baz	baz()	Add parentheses.	Swift
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
let msg = String::from("test"); let ref=&msg; msg.push_str("!");	let mut msg = String::from("test"); let ref=&msg; println!("{{}}", ref); msg.push_str("!");	Cannot mutate while borrowed.	Rust
SELECT * FROM products WHRE status=25;	SELECT * FROM products WHERE status=25;	Fix WHERE.	SQL
val b = 22; b = 96	var b = 22; b = 96	Use var for reassignment.	Scala
var num int = 'world'	var num string = 'world'	Type mismatch.	Go
println('test')	println("test")	Double quotes.	Scala
int* obj = nullptr; *obj=5;	int* obj = new int; *obj=5;	Allocate memory.	C++
if (b = 67) {{}}	if (b === 67) {{}}	Use === for equality.	JavaScript
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
list[85]	if (list.indices.contains(85)) list[85]	Check index.	Kotlin
DELETE FROM users WHERE age=55	DELETE FROM users WHERE age=55;	Add semicolon.	SQL
void main() {{ print('result') }}	void main() {{ print('result'); }}	Add semicolon.	Dart
<div color=red>	<div style='color:red;'>	Use style attribute.	CSS
void foo(); int main(){{foo();}}	void foo(); // prototype int main(){{foo();}}	Declare before use.	C++
Order.save();	Order.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
// comment	/* comment */	Use /* */.	CSS
<br></br>	<br>	Self-closing.	HTML
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
INSERT INTO products VALUES ('data',34)	INSERT INTO products (name, status) VALUES ('data',34);	Specify columns.	SQL
local item = 35	local item = 35	Correct.	Lua
'hello' + 44	'hello' + 44.to_s	Convert int.	Ruby
for i=1,12 do print(i) end	for i=1,12 do print(i) end	Correct.	Lua
if (temp = 51)	if (temp == 51)	Use ==.	C++
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
const count;	const count = 73;	Initialize const.	JavaScript
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
disp('world')	disp('world')	Correct.	MATLAB
if (count = 46)	if (count == 46)	Use ==.	Scala
print 'hello'	print('hello')	Parentheses for function call.	Lua
my @arr = (8,85,31);	my @arr = (8,85,31);	Correct.	Perl
<hr></hr>	<hr>	Self-closing.	HTML
const http = require('http'); http.createServer((req,res) => res.end('data')).listen(91);	const http = require('http'); http.createServer((req,res) => res.end('data')).listen(91);	Correct.	Node.js
UPDATE products SET email='output' WHERE status=6	UPDATE products SET email='output' WHERE status=6;	Add semicolon.	SQL
class Order {{ int foo; }} obj.foo=5;	class Order {{ public int foo; }} obj.foo=5;	Make field public.	Java
let count: number \| null = null; count.toFixed(97);	let count: number \| null = null; if(count!==null) count.toFixed(97);	Null check.	TypeScript
const user:Person = {{name:'test'}};	const user:Person = {{name:'test', age:15}};	Add missing property.	TypeScript
cin >> bar;	int bar; cin >> bar;	Declare variable.	C++
'90' + 28	90 + 28	Avoid string coercion.	JavaScript
class Child Model:	class Child(Model):	Inheritance uses parentheses.	Python
{{'status':5, 'title' 80}}	{{'status':5, 'title':80}}	Colon missing.	Python
let z = 74; z += 1;	let mut z = 74; z += 1;	Need mut to modify.	Rust
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
if (result = 84) {{}}	if (result == 84) {{}}	Use ==.	Kotlin
for (y in values)	for (y of values)	for...in iterates keys.	JavaScript
if (c = 26) {{}}	if (c == 26) {{}}	Use ==.	Java
{{'id':'world'}}	{{"id":"world"}}	Use double quotes.	JSON
$foo = 61; if ($foo = 61) {{}}	$foo = 61; if ($foo == 61) {{}}	Use ==.	PHP
if val = 24:	if val == 24:	Use == for comparison.	Python
[x*x for x in items if x > 38]	[x*x for x in items if x > 38]	Correct list comprehension.	Python
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
let result: Int = 'world'	let result: String = 'world'	Fix type.	Swift
String c = 'hello';	String c = "hello";	Double quotes.	Java
bar	bar()	Add parentheses.	Kotlin
if c = 3	if c == 3	Use ==.	Ruby
items(76)	if length(items) >= 76, items(76), end	Check length.	MATLAB
def test(c): return c + 1	def test(c): return c + 1	Correct.	Python
if [ $count = 32 ]; then	if [ "$count" = 32 ]; then	Quote variable.	Shell
function baz() {{ return {{key:'test'}} }}	function baz() {{ return {{key:'test'}}; }}	Return object on same line.	JavaScript
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
#footer {{ color: #fff; }}	#footer {{ color: #fff; }}	Correct.	CSS
String name = 'world';	String name = 'world';	Correct.	Dart
if (b = 13)	if (b == 13)	Use ==.	R
if data = 13 then print('result') end	if data == 13 then print('result') end	Use ==.	Lua
<note name='value'/>	<note name="value"/>	Double quotes.	XML
SELECT COUNT(*) FROM users	SELECT COUNT(*) FROM users;	Missing semicolon.	SQL
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
[27, 13, 21	[27, 13, 21]	Close bracket.	Ruby
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
print('output')	print('output')	Correct.	R
{ "name": "result" }	{ "name": "result" }	Correct.	JSON
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
while bar > 20 bar -= 1	while bar > 20: bar -= 1	Colon missing after while.	Python
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
def baz puts 'output' end	def baz puts 'output' end	Correct.	Ruby
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
List(80,61,69)	List(80,61,69)	Correct.	Scala
name: result age: 43	name: result age: 43	Correct.	YAML
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
z > 67 & z < 41	z > 67 and z < 41	Use 'and' not '&'.	Python
let bar = 54; let bar = 13;	let bar = 54; bar = 13;	Duplicate declaration.	JavaScript
let mut b=68; let ref1=&mut b; let r2=&mut b;	let mut b=68; {{ let ref1=&mut b; }} let r2=&mut b;	Only one mutable borrow.	Rust
if ($item = 96) {{}}	if ($item -eq 96) {{}}	Use -eq.	PowerShell
x = test	x = 'test'	Quote strings.	Python
{{"status":"output" "id":19}}	{{"status":"output", "id":19}}	Add comma.	JSON
class Product def method end end	class Product def method end end	Correct.	Ruby

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

Correct.

Java

let index = 'test'

let index = "test"

Double quotes.

Swift

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

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

Initialize variable.

Java

print 'hello'

print 'hello';

Add semicolon.

Perl

class Person {{ int c; }} obj.c=5;

class Person {{ public int c; }} obj.c=5;

Make field public.

Java

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

Correct.

PowerShell

let val = 89;

Correct.

JavaScript

SELECT age role FROM products;

SELECT age, role FROM products;

Add comma.

SQL

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

Correct.

R

x := 95

Correct.

Go

fmt.Println 'value'

fmt.Println('value')

Missing parentheses.

Go

Add alt text.

HTML

Quote attribute.

XML

val == '93'

val === 93

Use strict equality.

JavaScript

baz

baz()

Add parentheses.

Swift

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

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

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

Cannot mutate while borrowed.

Rust

SELECT * FROM products WHRE status=25;

SELECT * FROM products WHERE status=25;

Fix WHERE.

SQL

val b = 22; b = 96

var b = 22; b = 96

Use var for reassignment.

Scala

var num int = 'world'

var num string = 'world'

Type mismatch.

Go

println('test')

println("test")

Double quotes.

Scala

int* obj = nullptr; *obj=5;

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

Allocate memory.

C++

if (b = 67) {{}}

if (b === 67) {{}}

Use === for equality.

JavaScript

package main func main() {{}}

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

Import needed.

Go

list[85]

if (list.indices.contains(85)) list[85]

Check index.

Kotlin

DELETE FROM users WHERE age=55

DELETE FROM users WHERE age=55;

Add semicolon.

SQL

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

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

Add semicolon.

Dart

Use style attribute.

CSS

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

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

Declare before use.

C++

Order.save();

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

Handle promise.

Node.js

// comment

/* comment */

Use /* */.

CSS

<br>

Self-closing.

HTML

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

Correct.

MATLAB

INSERT INTO products VALUES ('data',34)

INSERT INTO products (name, status) VALUES ('data',34);

Specify columns.

SQL

local item = 35

Correct.

Lua

'hello' + 44

'hello' + 44.to_s

Convert int.

Ruby

for i=1,12 do print(i) end

Correct.

Lua

if (temp = 51)

if (temp == 51)

Use ==.

C++

int main() {{ return 0; }}

Correct.

C++

const count;

const count = 73;

Initialize const.

JavaScript

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

disp('world')

Correct.

MATLAB

if (count = 46)

if (count == 46)

Use ==.

Scala

print 'hello'

print('hello')

Parentheses for function call.

Lua

my @arr = (8,85,31);

Correct.

Perl

<hr>

Self-closing.

HTML

const http = require('http'); http.createServer((req,res) => res.end('data')).listen(91);

Correct.

Node.js

UPDATE products SET email='output' WHERE status=6

UPDATE products SET email='output' WHERE status=6;

Add semicolon.

SQL

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

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

Make field public.

Java

let count: number | null = null; count.toFixed(97);

let count: number | null = null; if(count!==null) count.toFixed(97);

Null check.

TypeScript

const user:Person = {{name:'test'}};

const user:Person = {{name:'test', age:15}};

Add missing property.

TypeScript

cin >> bar;

int bar; cin >> bar;

Declare variable.

C++

'90' + 28

90 + 28

Avoid string coercion.

JavaScript

class Child Model:

class Child(Model):

Inheritance uses parentheses.

Python

Colon missing.

Python

let z = 74; z += 1;

let mut z = 74; z += 1;

Need mut to modify.

Rust

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

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

Type not in union.

TypeScript

if (result = 84) {{}}

if (result == 84) {{}}

Use ==.

Kotlin

for (y in values)

for (y of values)

for...in iterates keys.

JavaScript

if (c = 26) {{}}

if (c == 26) {{}}

Use ==.

Java

Use double quotes.

JSON

$foo = 61; if ($foo = 61) {{}}

$foo = 61; if ($foo == 61) {{}}

Use ==.

PHP

if val = 24:

if val == 24:

Use == for comparison.

Python

[x*x for x in items if x > 38]

Correct list comprehension.

Python

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

let result: Int = 'world'

let result: String = 'world'

Fix type.

Swift

String c = 'hello';

String c = "hello";

Double quotes.

Java

bar

bar()

Add parentheses.

Kotlin

if c = 3

if c == 3

Use ==.

Ruby

items(76)

if length(items) >= 76, items(76), end

Check length.

MATLAB

def test(c): return c + 1

Correct.

Python

if [ $count = 32 ]; then

if [ "$count" = 32 ]; then

Quote variable.

Shell

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

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

Return object on same line.

JavaScript

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

#footer {{ color: #fff; }}

Correct.

CSS

String name = 'world';

Correct.

Dart

if (b = 13)

if (b == 13)

Use ==.

R

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

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

Use ==.

Lua

Double quotes.

XML

SELECT COUNT(*) FROM users

SELECT COUNT(*) FROM users;

Missing semicolon.

SQL

ArrayList list = new ArrayList();

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

Use generics.

Java

[27, 13, 21

[27, 13, 21]

Close bracket.

Ruby

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

print('output')

Correct.

R

{ "name": "result" }

Correct.

JSON

Correct.

XML

while bar > 20 bar -= 1

while bar > 20: bar -= 1

Colon missing after while.

Python

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

Correct.

CSS

def baz puts 'output' end

Correct.

Ruby

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

Correct.

PowerShell

List(80,61,69)

Correct.

Scala

name: result age: 43

Correct.

YAML

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

Correct.

Java

z > 67 & z < 41

z > 67 and z < 41

Use 'and' not '&'.

Python

let bar = 54; let bar = 13;

let bar = 54; bar = 13;

Duplicate declaration.

JavaScript

let mut b=68; let ref1=&mut b; let r2=&mut b;

let mut b=68; {{ let ref1=&mut b; }} let r2=&mut b;

Only one mutable borrow.

Rust

if ($item = 96) {{}}

if ($item -eq 96) {{}}

Use -eq.

PowerShell

x = test

x = 'test'

Quote strings.

Python

Add comma.

JSON

class Product def method end end

Correct.

Ruby