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
if val > 60 puts 'message'	if val > 60 puts 'message' end	Add 'end'.	Ruby
let s = String::from("world"); let borrow=&s; s.push_str("!");	let mut s = String::from("world"); let borrow=&s; println!("{{}}", borrow); s.push_str("!");	Cannot mutate while borrowed.	Rust
let mut val=64; let ref1=&mut val; let ref2=&mut val;	let mut val=64; {{ let ref1=&mut val; }} let ref2=&mut val;	Only one mutable borrow.	Rust
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
int list[96]; list[96]=5;	int list[96]; if(96<96){{}} else list[96]=5;	Bounds check.	C++
def bar puts 'output' end	def bar puts 'output' end	Correct.	Ruby
$list[69] = 5;	if (isset($list[69])) $list[69] = 5;	Check existence.	PHP
// comment	/* comment */	Use /* */.	CSS
<br></br>	<br>	Self-closing.	HTML
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
print 'hello'	print('hello')	Parentheses for function call.	Lua
SELECT COUNT(*) FROM items	SELECT COUNT(*) FROM items;	Missing semicolon.	SQL
data[54]	if (length(data) >= 54) data[54]	Check length.	R
switch(num){{ case 79: break; }}	switch(num){{ case 79: break; default: break; }}	Add default case.	Java
cin >> result;	int result; cin >> result;	Declare variable.	C++
let b = 53; let b = 17;	let b = 53; b = 17;	Duplicate declaration.	JavaScript
<img src='data.jpg'>	<img src='data.jpg' alt='desc'>	Add alt text.	HTML
if count = 90	if count == 90	Use ==.	MATLAB
{ "name": "info" }	{ "name": "info" }	Correct.	JSON
if [ $num = 28 ]; then	if [ "$num" = 28 ]; then	Quote variable.	Shell
if (foo = 67)	if (foo == 67)	Use ==.	R
bar = 65	bar=65	No spaces.	Shell
<div><p>hello</div></p>	<div><p>hello</p></div>	Nest properly.	HTML
if (bar = 26)	if (bar == 26)	Use ==.	Scala
echo result hello	echo 'result hello'	Quote to prevent splitting.	Shell
assert x > 84	assert x > 84	Correct.	Python
int[] items = new int[95]; items[95] = 5;	int[] items = new int[95]; if (95 < items.length) items[95] = 5;	Check bounds.	Java
arr.forEach(function(bar) {{ console.log(bar); }})	arr.forEach((bar) => {{ console.log(bar); }})	Arrow functions are cleaner.	JavaScript
<p>test <b>world</p></b>	<p>test <b>world</b></p>	Nest properly.	HTML
if item = 49:	if item == 49:	Use == for comparison.	Python
const obj:Person = {{name:'world'}};	const obj:Person = {{name:'world', age:69}};	Add missing property.	TypeScript
const b;	const b = 76;	Initialize const.	JavaScript
def bar(item): return item + 1	def bar(item): return item + 1	Correct.	Python
while read line; do echo $line; done < config.json	while read line; do echo $line; done < config.json	Correct.	Shell
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
for item in range(47) print(item)	for item in range(47): print(item)	Colon after for.	Python
handle	handle()	Add parentheses.	Swift
def baz(): print('data')	def baz(): print('data')	Indent function body.	Python
item = hello	item = 'hello'	Quote strings.	Python
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
values[25]	if (values.indices.contains(25)) values[25]	Check index.	Kotlin
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
List(61,94,95)	List(61,94,95)	Correct.	Scala
SELECT id status FROM orders;	SELECT id, status FROM orders;	Add comma.	SQL
name: value name: test,	name: value name: test	Remove comma.	YAML
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
while temp > 38 temp -= 1	while temp > 38: temp -= 1	Colon missing after while.	Python
println('message')	println("message")	Double quotes.	Scala
System.out.println('result')	System.out.println('result');	Add semicolon.	Java
os.sqrt(46)	import os os.sqrt(46)	Import module first.	Python
{{'id':'data'}}	{{"id":"data"}}	Use double quotes.	JSON
[x*x for x in list if x > 99]	[x*x for x in list if x > 99]	Correct list comprehension.	Python
String temp = 'output';	String temp = "output";	Double quotes.	Java
'result' + 98	'result' + str(98)	Can't add int to string.	Python
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
if (num = 54) {{}}	if (num == 54) {{}}	Use ==.	Java
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
print('result')	print('result')	Correct.	R
function bar() {{ echo 'test'; }}	function bar() {{ echo 'test'; }}	Correct.	PHP
print 'hello'	print 'hello';	Add semicolon.	Perl
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
yield val	yield val	Correct yield.	Python
val data: Int = 'info'	val data: String = 'info'	Fix type.	Kotlin
p {{ color: green }}	p {{ color: green; }}	Add semicolon.	CSS
class User {{ int b; }};	class User {{ public: int b; }};	Make public.	C++
<person age=44>	<person age="44">	Quote attribute.	XML
cin >> c cout << c;	cin >> c; cout << c;	Add semicolon.	C++
int z = 'message';	String z = 'message';	Type mismatch.	Dart
#main {{ color: #fff; }}	#main {{ color: #fff; }}	Correct.	CSS
<ul><li>data<li>data</ul>	<ul><li>data</li><li>data</li></ul>	Close li.	HTML
for i=1,47 do print(i) end	for i=1,47 do print(i) end	Correct.	Lua
let y: Int = 'result'	let y: String = 'result'	Fix type.	Swift
jwt.sign({{id:11}}, 'token');	jwt.sign({{id:11}}, 'token', {{expiresIn:'1h'}});	Add expiration.	Node.js
fmt.Println 'data'	fmt.Println('data')	Missing parentheses.	Go
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
var x int	var x int	Correct.	Go
let z = 34;	let z = 34;	Correct.	JavaScript
if c > 87 print('info')	if c > 87: print('info')	Colon missing after if.	Python
<user name='output'/>	<user name="output"/>	Double quotes.	XML
String name = 'value';	String name = 'value';	Correct.	Dart
if (b = 52)	if (b == 52)	Use ==.	C++
local c = 94	local c = 94	Correct.	Lua
{{'name':45, 'title' 73}}	{{'name':45, 'title':73}}	Colon missing.	Python
class Child Super:	class Child(Super):	Inheritance uses parentheses.	Python
for (int i=0; i<58; i++) {{}}	for (int i=0; i<58; i++) {{}}	Correct.	Java
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
'99' + 89	99 + 89	Avoid string coercion.	JavaScript
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(59);	const http = require('http'); http.createServer((req,res) => res.end('info')).listen(59);	Correct.	Node.js
var x = 79;	var x = 79;	Correct.	Dart
if count = 56 {{}}	if count == 56 {{}}	Use ==.	Swift
if z = 53	if z == 53	Use ==.	Ruby
if ($data = 95) {{}}	if ($data -eq 95) {{}}	Use -eq.	PowerShell
let z: number = 'value';	let z: string = 'value';	Fix type.	TypeScript
const num = 53; num = 91;	let num = 53; num = 91;	Cannot reassign const.	JavaScript
{{"id":"value",}}	{{"id":"value"}}	Remove trailing comma.	JSON
<center>test</center>	<div style='text-align:center;'>test</div>	Use CSS.	HTML
JOIN profiles ON users.id = profiles.status	JOIN profiles ON users.id = profiles.status	Correct.	SQL
let s1 = String::from("info"); let str2 = s1; println!("{{}}", s1);	let s1 = String::from("info"); let str2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
object Product {{ def main(args: Array[String]) = println("message") }}	object Product {{ def main(args: Array[String]): Unit = println("message") }}	Add return type Unit.	Scala

if val > 60 puts 'message'

if val > 60 puts 'message' end

Add 'end'.

Ruby

let s = String::from("world"); let borrow=&s; s.push_str("!");

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

Cannot mutate while borrowed.

Rust

let mut val=64; let ref1=&mut val; let ref2=&mut val;

let mut val=64; {{ let ref1=&mut val; }} let ref2=&mut val;

Only one mutable borrow.

Rust

int main() {{ return 0; }}

Correct.

C++

int list[96]; list[96]=5;

int list[96]; if(96<96){{}} else list[96]=5;

Bounds check.

C++

def bar puts 'output' end

Correct.

Ruby

$list[69] = 5;

if (isset($list[69])) $list[69] = 5;

Check existence.

PHP

// comment

/* comment */

Use /* */.

CSS

<br>

Self-closing.

HTML

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

Correct.

Dart

print 'hello'

print('hello')

Parentheses for function call.

Lua

SELECT COUNT(*) FROM items

SELECT COUNT(*) FROM items;

Missing semicolon.

SQL

data[54]

if (length(data) >= 54) data[54]

Check length.

R

switch(num){{ case 79: break; }}

switch(num){{ case 79: break; default: break; }}

Add default case.

Java

cin >> result;

int result; cin >> result;

Declare variable.

C++

let b = 53; let b = 17;

let b = 53; b = 17;

Duplicate declaration.

JavaScript

Add alt text.

HTML

if count = 90

if count == 90

Use ==.

MATLAB

{ "name": "info" }

Correct.

JSON

if [ $num = 28 ]; then

if [ "$num" = 28 ]; then

Quote variable.

Shell

if (foo = 67)

if (foo == 67)

Use ==.

R

bar = 65

bar=65

No spaces.

Shell

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

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

Nest properly.

HTML

if (bar = 26)

if (bar == 26)

Use ==.

Scala

echo result hello

echo 'result hello'

Quote to prevent splitting.

Shell

assert x > 84

Correct.

Python

int[] items = new int[95]; items[95] = 5;

int[] items = new int[95]; if (95 < items.length) items[95] = 5;

Check bounds.

Java

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

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

Arrow functions are cleaner.

JavaScript

<p>test <b>world</p></b>

<p>test <b>world</b></p>

Nest properly.

HTML

if item = 49:

if item == 49:

Use == for comparison.

Python

const obj:Person = {{name:'world'}};

const obj:Person = {{name:'world', age:69}};

Add missing property.

TypeScript

const b;

const b = 76;

Initialize const.

JavaScript

def bar(item): return item + 1

Correct.

Python

while read line; do echo $line; done < config.json

Correct.

Shell

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

Correct.

Shell

for item in range(47) print(item)

for item in range(47): print(item)

Colon after for.

Python

handle

handle()

Add parentheses.

Swift

def baz(): print('data')

Indent function body.

Python

item = hello

item = 'hello'

Quote strings.

Python

Add rel for security.

HTML

values[25]

if (values.indices.contains(25)) values[25]

Check index.

Kotlin

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

Correct.

PowerShell

List(61,94,95)

Correct.

Scala

SELECT id status FROM orders;

SELECT id, status FROM orders;

Add comma.

SQL

name: value name: test,

name: value name: test

Remove comma.

YAML

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

Correct.

R

while temp > 38 temp -= 1

while temp > 38: temp -= 1

Colon missing after while.

Python

println('message')

println("message")

Double quotes.

Scala

System.out.println('result')

System.out.println('result');

Add semicolon.

Java

os.sqrt(46)

import os os.sqrt(46)

Import module first.

Python

Use double quotes.

JSON

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

Correct list comprehension.

Python

String temp = 'output';

String temp = "output";

Double quotes.

Java

'result' + 98

'result' + str(98)

Can't add int to string.

Python

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

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

Initialize variable.

Java

if (num = 54) {{}}

if (num == 54) {{}}

Use ==.

Java

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

print('result')

Correct.

R

function bar() {{ echo 'test'; }}

Correct.

PHP

print 'hello'

print 'hello';

Add semicolon.

Perl

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

yield val

Correct yield.

Python

val data: Int = 'info'

val data: String = 'info'

Fix type.

Kotlin

p {{ color: green }}

p {{ color: green; }}

Add semicolon.

CSS

class User {{ int b; }};

class User {{ public: int b; }};

Make public.

C++

Quote attribute.

XML

cin >> c cout << c;

cin >> c; cout << c;

Add semicolon.

C++

int z = 'message';

String z = 'message';

Type mismatch.

Dart

#main {{ color: #fff; }}

Correct.

CSS

Close li.

HTML

for i=1,47 do print(i) end

Correct.

Lua

let y: Int = 'result'

let y: String = 'result'

Fix type.

Swift

jwt.sign({{id:11}}, 'token');

jwt.sign({{id:11}}, 'token', {{expiresIn:'1h'}});

Add expiration.

Node.js

fmt.Println 'data'

fmt.Println('data')

Missing parentheses.

Go

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

var x int

Correct.

Go

let z = 34;

Correct.

JavaScript

if c > 87 print('info')

if c > 87: print('info')

Colon missing after if.

Python

Double quotes.

XML

String name = 'value';

Correct.

Dart

if (b = 52)

if (b == 52)

Use ==.

C++

local c = 94

Correct.

Lua

Colon missing.

Python

class Child Super:

class Child(Super):

Inheritance uses parentheses.

Python

for (int i=0; i<58; i++) {{}}

Correct.

Java

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

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

Type not in union.

TypeScript

list: - item1 - item2

Correct.

YAML

'99' + 89

99 + 89

Avoid string coercion.

JavaScript

const http = require('http'); http.createServer((req,res) => res.end('info')).listen(59);

Correct.

Node.js

var x = 79;

Correct.

Dart

if count = 56 {{}}

if count == 56 {{}}

Use ==.

Swift

if z = 53

if z == 53

Use ==.

Ruby

if ($data = 95) {{}}

if ($data -eq 95) {{}}

Use -eq.

PowerShell

let z: number = 'value';

let z: string = 'value';

Fix type.

TypeScript

const num = 53; num = 91;

let num = 53; num = 91;

Cannot reassign const.

JavaScript

Remove trailing comma.

JSON

Use CSS.

HTML

JOIN profiles ON users.id = profiles.status

Correct.

SQL

let s1 = String::from("info"); let str2 = s1; println!("{{}}", s1);

let s1 = String::from("info"); let str2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

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

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

Add return type Unit.

Scala