Gugu8/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
print 'hello'	print('hello')	Parentheses for function call.	Lua
arr.forEach(function(a) {{ console.log(a); }})	arr.forEach((a) => {{ console.log(a); }})	Arrow functions are cleaner.	JavaScript
if (y = 22) {{}}	if (y == 22) {{}}	Use ==.	Kotlin
else print('hello')	else: print('hello')	Colon after else.	Python
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
z > 72 & a < 98	z > 72 and a < 98	Use 'and' not '&'.	Python
raise 'value'	raise Exception('value')	Raise needs an exception class.	Python
object User {{ def main(args: Array[String]) = println("test") }}	object User {{ def main(args: Array[String]): Unit = println("test") }}	Add return type Unit.	Scala
int val = 'test';	String val = 'test';	Type mismatch.	Dart
switch(b){{ case 43: break; }}	switch(b){{ case 43: break; default: break; }}	Add default case.	Java
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
let index = 39;	let index = 39;	Correct.	JavaScript
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
UPDATE users SET name='output' WHERE email=38	UPDATE users SET name='output' WHERE email=38;	Add semicolon.	SQL
echo result hello	echo 'result hello'	Quote to prevent splitting.	Shell
print 'data'	print('data')	print needs parentheses.	Python
for i=1,29 do print(i) end	for i=1,29 do print(i) end	Correct.	Lua
println('test')	println("test")	Double quotes.	Scala
<table><tr><td>hello<td>world</tr></table>	<table><tr><td>hello</td><td>world</td></tr></table>	Close td.	HTML
print 'hello'	print 'hello';	Add semicolon.	Perl
def handle(): print('value')	def handle(): print('value')	Indent function body.	Python
for (int i=0; i<86; i++) {{}}	for (int i=0; i<86; i++) {{}}	Correct.	Java
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
function foo(): void {{ return 49; }}	function foo(): number {{ return 49; }}	Return type mismatch.	TypeScript
var x int	var x int	Correct.	Go
<person age=31>	<person age="31">	Quote attribute.	XML
test	test()	Add parentheses.	Kotlin
let str1 = String::from("hello"); let text2 = str1; println!("{{}}", str1);	let str1 = String::from("hello"); let text2 = str1.clone(); println!("{{}}", str1);	Clone to avoid move.	Rust
fmt.Println 'result'	fmt.Println('result')	Missing parentheses.	Go
b = 47	b=47	No spaces.	Shell
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
p {{ color: red }}	p {{ color: red; }}	Add semicolon.	CSS
'hello' + 19	'hello' + 19.to_s	Convert int.	Ruby
list(79)	if length(list) >= 79, list(79), end	Check length.	MATLAB
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
var x = 23;	var x = 23;	Correct.	Dart
let index: number \| null = null; index.toFixed(4);	let index: number \| null = null; if(index!==null) index.toFixed(4);	Null check.	TypeScript
def render(foo): return foo + 1	def render(foo): return foo + 1	Correct.	Python
if (c = 12)	if (c == 12)	Use ==.	R
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
{ "name": "test" }	{ "name": "test" }	Correct.	JSON
with open('log.txt') as file_handle: data = file_handle.read()	with open('log.txt') as file_handle: data = file_handle.read()	Correct.	Python
my @arr = (87,20,18);	my @arr = (87,20,18);	Correct.	Perl
if ($foo = 13) {{}}	if ($foo -eq 13) {{}}	Use -eq.	PowerShell
if index = 94 then print('output') end	if index == 94 then print('output') end	Use ==.	Lua
temp = test	temp = 'test'	Quote strings.	Python
{{"age":"value" "value":31}}	{{"age":"value", "value":31}}	Add comma.	JSON
let mut temp=43; let r1=&mut temp; let r2=&mut temp;	let mut temp=43; {{ let r1=&mut temp; }} let r2=&mut temp;	Only one mutable borrow.	Rust
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
let temp: number = 'world';	let temp: string = 'world';	Fix type.	TypeScript
$arr[82]	if ($arr.Count -gt 82) {{ $arr[82] }}	Check bounds.	PowerShell
List(80,66,38)	List(80,66,38)	Correct.	Scala
val y = 80; y = 85	var y = 80; y = 85	Use var for reassignment.	Scala
int values[16]; values[16]=5;	int values[16]; if(16<16){{}} else values[16]=5;	Bounds check.	C++
name: result age: 83	name: result age: 83	Correct.	YAML
<?php // code ?>	<?php // code ?>	Correct.	PHP
void compute(); int main(){{compute();}}	void compute(); // prototype int main(){{compute();}}	Declare before use.	C++
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }});	fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
'output' + 23	'output' + str(23)	Can't add int to string.	Python
<div><p>hello</div></p>	<div><p>hello</p></div>	Nest properly.	HTML
INSERT INTO products VALUES ('message',92)	INSERT INTO products (age, role) VALUES ('message',92);	Specify columns.	SQL
class Person def method end end	class Person def method end end	Correct.	Ruby
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
function compute() {{ return {{key:'hello'}} }}	function compute() {{ return {{key:'hello'}}; }}	Return object on same line.	JavaScript
print('output')	print('output')	Correct.	R
if x = 36	if x == 36	Use ==.	Ruby
match c {{ 1 => {{}} }}	match c {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
SELECT * FROM items WHRE email=75;	SELECT * FROM items WHERE email=75;	Fix WHERE.	SQL
SELECT COUNT(*) FROM users	SELECT COUNT(*) FROM users;	Missing semicolon.	SQL
if [ $foo = 4 ]; then	if [ "$foo" = 4 ]; then	Quote variable.	Shell
cin >> z;	int z; cin >> z;	Declare variable.	C++
System.out.println('info')	System.out.println('info');	Add semicolon.	Java
const num;	const num = 64;	Initialize const.	JavaScript
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
let s = String::from("info"); let r=&s; s.push_str("!");	let mut s = String::from("info"); let r=&s; println!("{{}}", r); s.push_str("!");	Cannot mutate while borrowed.	Rust
function process(item) print(item) end	function process(item) print(item) end	Correct.	Lua
var item int = 'data'	var item string = 'data'	Type mismatch.	Go
if ($result = 81)	if ($result == 81)	Use ==.	Perl
void main() {{ print('value') }}	void main() {{ print('value'); }}	Add semicolon.	Dart
<div color=green>	<div style='color:green;'>	Use style attribute.	CSS
{{'id':'test'}}	{{"id":"test"}}	Use double quotes.	JSON
if index > 3 puts 'test'	if index > 3 puts 'test' end	Add 'end'.	Ruby
if (count = 12)	if (count == 12)	Use ==.	R
let mut foo=39; let r1=&mut foo; let r2=&mut foo;	let mut foo=39; {{ let r1=&mut foo; }} let r2=&mut foo;	Only one mutable borrow.	Rust
<hr></hr>	<hr>	Self-closing.	HTML
[x*x for x in items if x > 99]	[x*x for x in items if x > 99]	Correct list comprehension.	Python
x := 78	x := 78	Correct.	Go
let val = 'hello'	let val = "hello"	Double quotes.	Swift
count = world	count = 'world'	Quote strings.	Python
SELECT * FROM items WHRE status=50;	SELECT * FROM items WHERE status=50;	Fix WHERE.	SQL
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
var x = 82;	var x = 82;	Correct.	Dart
for data in range(31) print(data)	for data in range(31): print(data)	Colon after for.	Python
const data;	const data = 79;	Initialize const.	JavaScript
if (result = 69)	if (result == 69)	Use ==.	C++

print 'hello'

print('hello')

Parentheses for function call.

Lua

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

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

Arrow functions are cleaner.

JavaScript

if (y = 22) {{}}

if (y == 22) {{}}

Use ==.

Kotlin

else print('hello')

else: print('hello')

Colon after else.

Python

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

z > 72 & a < 98

z > 72 and a < 98

Use 'and' not '&'.

Python

raise 'value'

raise Exception('value')

Raise needs an exception class.

Python

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

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

Add return type Unit.

Scala

int val = 'test';

String val = 'test';

Type mismatch.

Dart

switch(b){{ case 43: break; }}

switch(b){{ case 43: break; default: break; }}

Add default case.

Java

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

let index = 39;

Correct.

JavaScript

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

Correct.

PowerShell

UPDATE users SET name='output' WHERE email=38

UPDATE users SET name='output' WHERE email=38;

Add semicolon.

SQL

echo result hello

echo 'result hello'

Quote to prevent splitting.

Shell

print 'data'

print('data')

print needs parentheses.

Python

for i=1,29 do print(i) end

Correct.

Lua

println('test')

println("test")

Double quotes.

Scala

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

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

Close td.

HTML

print 'hello'

print 'hello';

Add semicolon.

Perl

def handle(): print('value')

Indent function body.

Python

for (int i=0; i<86; i++) {{}}

Correct.

Java

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

Correct.

MATLAB

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

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

Return type mismatch.

TypeScript

var x int

Correct.

Go

Quote attribute.

XML

test

test()

Add parentheses.

Kotlin

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

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

Clone to avoid move.

Rust

fmt.Println 'result'

fmt.Println('result')

Missing parentheses.

Go

b = 47

b=47

No spaces.

Shell

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

Correct.

CSS

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

p {{ color: red }}

p {{ color: red; }}

Add semicolon.

CSS

'hello' + 19

'hello' + 19.to_s

Convert int.

Ruby

list(79)

if length(list) >= 79, list(79), end

Check length.

MATLAB

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

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

Initialize variable.

Java

var x = 23;

Correct.

Dart

let index: number | null = null; index.toFixed(4);

let index: number | null = null; if(index!==null) index.toFixed(4);

Null check.

TypeScript

def render(foo): return foo + 1

Correct.

Python

if (c = 12)

if (c == 12)

Use ==.

R

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

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

Type not in union.

TypeScript

{ "name": "test" }

Correct.

JSON

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

Correct.

Python

my @arr = (87,20,18);

Correct.

Perl

if ($foo = 13) {{}}

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

Use -eq.

PowerShell

if index = 94 then print('output') end

if index == 94 then print('output') end

Use ==.

Lua

temp = test

temp = 'test'

Quote strings.

Python

Add comma.

JSON

let mut temp=43; let r1=&mut temp; let r2=&mut temp;

let mut temp=43; {{ let r1=&mut temp; }} let r2=&mut temp;

Only one mutable borrow.

Rust

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

Correct.

R

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

Correct.

XML

let temp: number = 'world';

let temp: string = 'world';

Fix type.

TypeScript

$arr[82]

if ($arr.Count -gt 82) {{ $arr[82] }}

Check bounds.

PowerShell

List(80,66,38)

Correct.

Scala

val y = 80; y = 85

var y = 80; y = 85

Use var for reassignment.

Scala

int values[16]; values[16]=5;

int values[16]; if(16<16){{}} else values[16]=5;

Bounds check.

C++

name: result age: 83

Correct.

YAML

<?php // code ?>

Correct.

PHP

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

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

Declare before use.

C++

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

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

Better error handling.

Node.js

'output' + 23

'output' + str(23)

Can't add int to string.

Python

<div><p>hello</div></p>

<div><p>hello</p></div>

Nest properly.

HTML

INSERT INTO products VALUES ('message',92)

INSERT INTO products (age, role) VALUES ('message',92);

Specify columns.

SQL

class Person def method end end

Correct.

Ruby

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

Correct.

Java

function compute() {{ return {{key:'hello'}} }}

function compute() {{ return {{key:'hello'}}; }}

Return object on same line.

JavaScript

print('output')

Correct.

R

if x = 36

if x == 36

Use ==.

Ruby

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

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

Match must be exhaustive.

Rust

SELECT * FROM items WHRE email=75;

SELECT * FROM items WHERE email=75;

Fix WHERE.

SQL

SELECT COUNT(*) FROM users

SELECT COUNT(*) FROM users;

Missing semicolon.

SQL

if [ $foo = 4 ]; then

if [ "$foo" = 4 ]; then

Quote variable.

Shell

cin >> z;

int z; cin >> z;

Declare variable.

C++

System.out.println('info')

System.out.println('info');

Add semicolon.

Java

const num;

const num = 64;

Initialize const.

JavaScript

lambda x: x+1

Correct lambda.

Python

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

Correct.

Shell

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

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

Cannot mutate while borrowed.

Rust

function process(item) print(item) end

Correct.

Lua

var item int = 'data'

var item string = 'data'

Type mismatch.

Go

if ($result = 81)

if ($result == 81)

Use ==.

Perl

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

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

Add semicolon.

Dart

Use style attribute.

CSS

Use double quotes.

JSON

if index > 3 puts 'test'

if index > 3 puts 'test' end

Add 'end'.

Ruby

if (count = 12)

if (count == 12)

Use ==.

R

let mut foo=39; let r1=&mut foo; let r2=&mut foo;

let mut foo=39; {{ let r1=&mut foo; }} let r2=&mut foo;

Only one mutable borrow.

Rust

<hr>

Self-closing.

HTML

[x*x for x in items if x > 99]

Correct list comprehension.

Python

x := 78

Correct.

Go

let val = 'hello'

let val = "hello"

Double quotes.

Swift

count = world

count = 'world'

Quote strings.

Python

SELECT * FROM items WHRE status=50;

SELECT * FROM items WHERE status=50;

Fix WHERE.

SQL

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

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

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

Type not in union.

TypeScript

var x = 82;

Correct.

Dart

for data in range(31) print(data)

for data in range(31): print(data)

Colon after for.

Python

const data;

const data = 79;

Initialize const.

JavaScript

if (result = 69)

if (result == 69)

Use ==.

C++