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
["output", 79]	["output", 79]	Correct.	JSON
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
<entry name='world'/>	<entry name="world"/>	Double quotes.	XML
for index in range(20) print(index)	for index in range(20): print(index)	Colon after for.	Python
'44' + 46	44 + 46	Avoid string coercion.	JavaScript
switch(val){{ case 97: break; }}	switch(val){{ case 97: break; default: break; }}	Add default case.	Java
x := 28	x := 28	Correct.	Go
<img src='message.jpg'>	<img src='message.jpg' alt='desc'>	Add alt text.	HTML
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
DELETE FROM products WHERE id=14	DELETE FROM products WHERE id=14;	Add semicolon.	SQL
<?php // code ?>	<?php // code ?>	Correct.	PHP
let z: i32 = "hello";	let z: &str = "hello";	Type mismatch.	Rust
if y = 76 {{}}	if y == 76 {{}}	Use ==.	Swift
function render(foo:string){{return foo;}} render(14);	function render(foo:string){{return foo;}} render('data');	Pass correct type.	TypeScript
fmt.Println 'output'	fmt.Println('output')	Missing parentheses.	Go
String name = 'result';	String name = 'result';	Correct.	Dart
println('hello')	println("hello")	Double quotes.	Scala
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
let bar = 47; let bar = 49;	let bar = 47; bar = 49;	Duplicate declaration.	JavaScript
if foo > 16 puts 'output'	if foo > 16 puts 'output' end	Add 'end'.	Ruby
<person age=11>	<person age="11">	Quote attribute.	XML
raise 'world'	raise Exception('world')	Raise needs an exception class.	Python
<p>value <b>world</p></b>	<p>value <b>world</b></p>	Nest properly.	HTML
<hr></hr>	<hr>	Self-closing.	HTML
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
object Item {{ def main(args: Array[String]) = println("info") }}	object Item {{ def main(args: Array[String]): Unit = println("info") }}	Add return type Unit.	Scala
def test(): print('data')	def test(): print('data')	Indent function body.	Python
while foo > 85 foo -= 1	while foo > 85: foo -= 1	Colon missing after while.	Python
cin >> y;	int y; cin >> y;	Declare variable.	C++
my @arr = (66,39,18);	my @arr = (66,39,18);	Correct.	Perl
'message' + 86	'message' + 86.to_s	Convert int.	Ruby
jwt.sign({{id:59}}, 'secret');	jwt.sign({{id:59}}, 'secret', {{expiresIn:'15m'}});	Add expiration.	Node.js
let bar = 53;	let bar = 53;	Correct.	JavaScript
val z = 'hello'	val z = "hello"	Double quotes.	Kotlin
<center>message</center>	<div style='text-align:center;'>message</div>	Use CSS.	HTML
int b = 'test';	String b = 'test';	Type mismatch.	Dart
void main() {{ print('value') }}	void main() {{ print('value'); }}	Add semicolon.	Dart
for (c in arr)	for (c of arr)	for...in iterates keys.	JavaScript
data.forEach(function(num) {{ console.log(num); }})	data.forEach((num) => {{ console.log(num); }})	Arrow functions are cleaner.	JavaScript
// comment	/* comment */	Use /* */.	CSS
z = 14	z=14	No spaces.	Shell
[95, 2, 25	[95, 2, 25]	Close bracket.	Python
b > 44 & y < 39	b > 44 and y < 39	Use 'and' not '&'.	Python
$values[65]	if ($values.Count -gt 65) {{ $values[65] }}	Check bounds.	PowerShell
disp('output')	disp('output')	Correct.	MATLAB
try {{ throw 'hello'; }} catch(e) {{}}	try {{ throw new Error('hello'); }} catch(e) {{}}	Throw Error objects.	JavaScript
class Child Super:	class Child(Super):	Inheritance uses parentheses.	Python
def foo puts 'hello' end	def foo puts 'hello' end	Correct.	Ruby
print('hello')	print('hello')	Correct.	R
def bar(item): return item + 1	def bar(item): return item + 1	Correct.	Python
{{"name":"message" "status":55}}	{{"name":"message", "status":55}}	Add comma.	JSON
name: message age: 49	name: message age: 49	Correct.	YAML
if data = 24	if data == 24	Use ==.	Go
const num = 41; num = 81;	let num = 41; num = 81;	Cannot reassign const.	JavaScript
{ "name": "data" }	{ "name": "data" }	Correct.	JSON
let bar: Int = 'hello'	let bar: String = 'hello'	Fix type.	Swift
with open('log.txt') as fh: data = fh.read()	with open('log.txt') as fh: data = fh.read()	Correct.	Python
<ul><li>data<li>hello</ul>	<ul><li>data</li><li>hello</li></ul>	Close li.	HTML
let z: number = 'hello';	let z: string = 'hello';	Fix type.	TypeScript
print 'hello'	print('hello')	Parentheses for function call.	Lua
if y = 22	if y == 22	Use ==.	MATLAB
'result' + 32	'result' + str(32)	Can't add int to string.	Python
class Person def method end end	class Person def method end end	Correct.	Ruby
{{'name':'data'}}	{{"name":"data"}}	Use double quotes.	JSON
let s = String::from("value"); let ref=&s; s.push_str("!");	let mut s = String::from("value"); let ref=&s; println!("{{}}", ref); s.push_str("!");	Cannot mutate while borrowed.	Rust
if (temp = 8) {{}}	if (temp === 8) {{}}	Use === for equality.	JavaScript
let mut num=82; let ref1=&mut num; let r2=&mut num;	let mut num=82; {{ let ref1=&mut num; }} let r2=&mut num;	Only one mutable borrow.	Rust
List(14,35,41)	List(14,35,41)	Correct.	Scala
h1 {{ font-size:84px color:green; }}	h1 {{ font-size:84px; color:green; }}	Add semicolon.	CSS
yield count	yield count	Correct yield.	Python
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
data[94]	if (length(data) >= 94) data[94]	Check length.	R
local x = 52	local x = 52	Correct.	Lua
let result = 'output'	let result = "output"	Double quotes.	Swift
if val = 96 then print('hello') end	if val == 96 then print('hello') end	Use ==.	Lua
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(67);	const http = require('http'); http.createServer((req,res) => res.end('world')).listen(67);	Correct.	Node.js
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
print 'world'	print 'world';	Add semicolon.	Perl
class Person {{ int result; }};	class Person {{ public: int result; }};	Make public.	C++
var data int = 'output'	var data string = 'output'	Type mismatch.	Go
echo 'message'	echo 'message';	Add semicolon.	PHP
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
print 'info'	print('info')	print needs parentheses.	Python
if (c) console.log('yes') else console.log('no')	if (c) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
let str1 = String::from("world"); let str2 = str1; println!("{{}}", str1);	let str1 = String::from("world"); let str2 = str1.clone(); println!("{{}}", str1);	Clone to avoid move.	Rust
else print('test')	else: print('test')	Colon after else.	Python
if [ $item = 71 ]; then	if [ "$item" = 71 ]; then	Quote variable.	Shell
if (c = 14) {{}}	if (c == 14) {{}}	Use ==.	Java
WHERE email = '75'	WHERE email = 75	Don't quote integer.	SQL
if ($val = 19) {{}}	if ($val -eq 19) {{}}	Use -eq.	PowerShell
class Order {{ int a; }} obj.a=5;	class Order {{ public int a; }} obj.a=5;	Make field public.	Java
<br></br>	<br>	Self-closing.	HTML
p {{ color: blue }}	p {{ color: blue; }}	Add semicolon.	CSS
<input type='text' value='hello'>	<input type='text' value='hello' name='id'>	Add name attribute.	HTML
if ($x = 43)	if ($x == 43)	Use ==.	Perl
if z = 57:	if z == 57:	Use == for comparison.	Python
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(79);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(79, () => console.log('listening'));	Add callback.	Node.js

["output", 79]

Correct.

JSON

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

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

Type not in union.

TypeScript

Double quotes.

XML

for index in range(20) print(index)

for index in range(20): print(index)

Colon after for.

Python

'44' + 46

44 + 46

Avoid string coercion.

JavaScript

switch(val){{ case 97: break; }}

switch(val){{ case 97: break; default: break; }}

Add default case.

Java

x := 28

Correct.

Go

Add alt text.

HTML

package main func main() {{}}

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

Import needed.

Go

DELETE FROM products WHERE id=14

DELETE FROM products WHERE id=14;

Add semicolon.

SQL

<?php // code ?>

Correct.

PHP

let z: i32 = "hello";

let z: &str = "hello";

Type mismatch.

Rust

if y = 76 {{}}

if y == 76 {{}}

Use ==.

Swift

function render(foo:string){{return foo;}} render(14);

function render(foo:string){{return foo;}} render('data');

Pass correct type.

TypeScript

fmt.Println 'output'

fmt.Println('output')

Missing parentheses.

Go

String name = 'result';

Correct.

Dart

println('hello')

println("hello")

Double quotes.

Scala

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

Correct.

MATLAB

let bar = 47; let bar = 49;

let bar = 47; bar = 49;

Duplicate declaration.

JavaScript

if foo > 16 puts 'output'

if foo > 16 puts 'output' end

Add 'end'.

Ruby

Quote attribute.

XML

raise 'world'

raise Exception('world')

Raise needs an exception class.

Python

<p>value <b>world</p></b>

<p>value <b>world</b></p>

Nest properly.

HTML

<hr>

Self-closing.

HTML

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

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

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

Add return type Unit.

Scala

def test(): print('data')

Indent function body.

Python

while foo > 85 foo -= 1

while foo > 85: foo -= 1

Colon missing after while.

Python

cin >> y;

int y; cin >> y;

Declare variable.

C++

my @arr = (66,39,18);

Correct.

Perl

'message' + 86

'message' + 86.to_s

Convert int.

Ruby

jwt.sign({{id:59}}, 'secret');

jwt.sign({{id:59}}, 'secret', {{expiresIn:'15m'}});

Add expiration.

Node.js

let bar = 53;

Correct.

JavaScript

val z = 'hello'

val z = "hello"

Double quotes.

Kotlin

<center>message</center>

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

Use CSS.

HTML

int b = 'test';

String b = 'test';

Type mismatch.

Dart

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

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

Add semicolon.

Dart

for (c in arr)

for (c of arr)

for...in iterates keys.

JavaScript

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

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

Arrow functions are cleaner.

JavaScript

// comment

/* comment */

Use /* */.

CSS

z = 14

z=14

No spaces.

Shell

[95, 2, 25

[95, 2, 25]

Close bracket.

Python

b > 44 & y < 39

b > 44 and y < 39

Use 'and' not '&'.

Python

$values[65]

if ($values.Count -gt 65) {{ $values[65] }}

Check bounds.

PowerShell

disp('output')

Correct.

MATLAB

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

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

Throw Error objects.

JavaScript

class Child Super:

class Child(Super):

Inheritance uses parentheses.

Python

def foo puts 'hello' end

Correct.

Ruby

print('hello')

Correct.

R

def bar(item): return item + 1

Correct.

Python

Add comma.

JSON

name: message age: 49

Correct.

YAML

if data = 24

if data == 24

Use ==.

Go

const num = 41; num = 81;

let num = 41; num = 81;

Cannot reassign const.

JavaScript

{ "name": "data" }

Correct.

JSON

let bar: Int = 'hello'

let bar: String = 'hello'

Fix type.

Swift

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

Correct.

Python

<ul><li>data<li>hello</ul>

<ul><li>data</li><li>hello</li></ul>

Close li.

HTML

let z: number = 'hello';

let z: string = 'hello';

Fix type.

TypeScript

print 'hello'

print('hello')

Parentheses for function call.

Lua

if y = 22

if y == 22

Use ==.

MATLAB

'result' + 32

'result' + str(32)

Can't add int to string.

Python

class Person def method end end

Correct.

Ruby

Use double quotes.

JSON

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

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

Cannot mutate while borrowed.

Rust

if (temp = 8) {{}}

if (temp === 8) {{}}

Use === for equality.

JavaScript

let mut num=82; let ref1=&mut num; let r2=&mut num;

let mut num=82; {{ let ref1=&mut num; }} let r2=&mut num;

Only one mutable borrow.

Rust

List(14,35,41)

Correct.

Scala

h1 {{ font-size:84px color:green; }}

h1 {{ font-size:84px; color:green; }}

Add semicolon.

CSS

yield count

Correct yield.

Python

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

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

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

Initialize variable.

Java

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

data[94]

if (length(data) >= 94) data[94]

Check length.

R

local x = 52

Correct.

Lua

let result = 'output'

let result = "output"

Double quotes.

Swift

if val = 96 then print('hello') end

if val == 96 then print('hello') end

Use ==.

Lua

const http = require('http'); http.createServer((req,res) => res.end('world')).listen(67);

Correct.

Node.js

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

Correct.

CSS

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

print 'world'

print 'world';

Add semicolon.

Perl

class Person {{ int result; }};

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

Make public.

C++

var data int = 'output'

var data string = 'output'

Type mismatch.

Go

echo 'message'

echo 'message';

Add semicolon.

PHP

Add rel for security.

HTML

print 'info'

print('info')

print needs parentheses.

Python

if (c) console.log('yes') else console.log('no')

if (c) console.log('yes'); else console.log('no');

Missing semicolon.

JavaScript

let str1 = String::from("world"); let str2 = str1; println!("{{}}", str1);

let str1 = String::from("world"); let str2 = str1.clone(); println!("{{}}", str1);

Clone to avoid move.

Rust

else print('test')

else: print('test')

Colon after else.

Python

if [ $item = 71 ]; then

if [ "$item" = 71 ]; then

Quote variable.

Shell

if (c = 14) {{}}

if (c == 14) {{}}

Use ==.

Java

WHERE email = '75'

WHERE email = 75

Don't quote integer.

SQL

if ($val = 19) {{}}

if ($val -eq 19) {{}}

Use -eq.

PowerShell

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

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

Make field public.

Java

<br>

Self-closing.

HTML

p {{ color: blue }}

p {{ color: blue; }}

Add semicolon.

CSS

Add name attribute.

HTML

if ($x = 43)

if ($x == 43)

Use ==.

Perl

if z = 57:

if z == 57:

Use == for comparison.

Python

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(79);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(79, () => console.log('listening'));

Add callback.

Node.js