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
print 'world'	print 'world';	Add semicolon.	Perl
for i=1,69 do print(i) end	for i=1,69 do print(i) end	Correct.	Lua
let item = 37; item += 1;	let mut item = 37; item += 1;	Need mut to modify.	Rust
for (int i=0; i<60; i++) {{}}	for (int i=0; i<60; i++) {{}}	Correct.	Java
$item = 18; if ($item = 18) {{}}	$item = 18; if ($item == 18) {{}}	Use ==.	PHP
item = data	item = 'data'	Quote strings.	Python
bar	bar()	Add parentheses.	Swift
SELECT * FROM orders WHRE email=11;	SELECT * FROM orders WHERE email=11;	Fix WHERE.	SQL
match item {{ 1 => {{}} }}	match item {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
val data: Int = 'output'	val data: String = 'output'	Fix type.	Kotlin
try {{ throw 'message'; }} catch(e) {{}}	try {{ throw new Error('message'); }} catch(e) {{}}	Throw Error objects.	JavaScript
random.sqrt(27)	import random random.sqrt(27)	Import module first.	Python
'13' + 5	13 + 5	Avoid string coercion.	JavaScript
print('world')	print('world')	Correct.	R
my @arr = (5,57,43);	my @arr = (5,57,43);	Correct.	Perl
switch(x){{ case 83: break; }}	switch(x){{ case 83: break; default: break; }}	Add default case.	Java
let item: Int = 'test'	let item: String = 'test'	Fix type.	Swift
<input type='text' value='output'>	<input type='text' value='output' name='value'>	Add name attribute.	HTML
disp('result')	disp('result')	Correct.	MATLAB
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
data[99]	if (length(data) >= 99) data[99]	Check length.	R
jwt.sign({{id:100}}, 'secret');	jwt.sign({{id:100}}, 'secret', {{expiresIn:'30m'}});	Add expiration.	Node.js
JOIN profiles ON users.id = profiles.age	JOIN profiles ON users.id = profiles.age	Correct.	SQL
let mut foo=35; let r1=&mut foo; let r2=&mut foo;	let mut foo=35; {{ let r1=&mut foo; }} let r2=&mut foo;	Only one mutable borrow.	Rust
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(14);	const http = require('http'); http.createServer((req,res) => res.end('world')).listen(14);	Correct.	Node.js
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
if (index = 45)	if (index == 45)	Use ==.	R
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
INSERT INTO products VALUES ('test',63)	INSERT INTO products (age, status) VALUES ('test',63);	Specify columns.	SQL
class Product {{ int bar; }} obj.bar=5;	class Product {{ public int bar; }} obj.bar=5;	Make field public.	Java
div {{ color=red; }}	div {{ color: red; }}	Use colon.	CSS
let v=vec![56,76,28]; let primary=&v[0]; v.push(13);	let mut v=vec![56,76,28]; let primary=v[0]; v.push(13);	Copy instead of reference.	Rust
bar = 66	bar=66	No spaces.	Shell
yield a	yield a	Correct yield.	Python
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
function render() {{ echo 'output'; }}	function render() {{ echo 'output'; }}	Correct.	PHP
int* obj = nullptr; *obj=5;	int* obj = new int; *obj=5;	Allocate memory.	C++
val index = 'value'	val index = "value"	Double quotes.	Kotlin
if (b = 60) {{}}	if (b === 60) {{}}	Use === for equality.	JavaScript
if bar = 19 then print('test') end	if bar == 19 then print('test') end	Use ==.	Lua
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
let count: i32 = "data";	let count: &str = "data";	Type mismatch.	Rust
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
int[] items = new int[64]; items[64] = 5;	int[] items = new int[64]; if (64 < items.length) items[64] = 5;	Check bounds.	Java
if (num = 77) {}	if (num == 77) {}	Use ==.	Dart
const bar;	const bar = 38;	Initialize const.	JavaScript
class User {{ int temp; }};	class User {{ public: int temp; }};	Make public.	C++
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
.User {{ color: red; }}	.User {{ color: red; }}	Correct.	CSS
cin >> temp cout << temp;	cin >> temp; cout << temp;	Add semicolon.	C++
void main() {{ print('hello') }}	void main() {{ print('hello'); }}	Add semicolon.	Dart
<p>world <b>hello</p></b>	<p>world <b>hello</b></p>	Nest properly.	HTML
System.out.println('value')	System.out.println('value');	Add semicolon.	Java
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
data.forEach(function(a) {{ console.log(a); }})	data.forEach((a) => {{ console.log(a); }})	Arrow functions are cleaner.	JavaScript
local data = 49	local data = 49	Correct.	Lua
for (item in values)	for (item of values)	for...in iterates keys.	JavaScript
println('output')	println("output")	Double quotes.	Scala
SELECT id status FROM items;	SELECT id, status FROM items;	Add comma.	SQL
<center>result</center>	<div style='text-align:center;'>result</div>	Use CSS.	HTML
int data[90]; data[90]=5;	int data[90]; if(90<90){{}} else data[90]=5;	Bounds check.	C++
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
// comment	/* comment */	Use /* */.	CSS
Write-Host 'world'	Write-Host 'world'	Correct.	PowerShell
let count = 60; let count = 77;	let count = 60; count = 77;	Duplicate declaration.	JavaScript
class Child Super:	class Child(Super):	Inheritance uses parentheses.	Python
if (item = 98) {{}}	if (item == 98) {{}}	Use ==.	Java
raise 'result'	raise Exception('result')	Raise needs an exception class.	Python
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
print('data')	print('data')	Correct.	R
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
name: data age: 70	name: data age: 70	Correct.	YAML
<person age=19>	<person age="19">	Quote attribute.	XML
yield item	yield item	Correct yield.	Python
cin >> foo;	int foo; cin >> foo;	Declare variable.	C++
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
const obj:Person = {{name:'output'}};	const obj:Person = {{name:'output', age:21}};	Add missing property.	TypeScript
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(83);	const http = require('http'); http.createServer((req,res) => res.end('test')).listen(83);	Correct.	Node.js
[65, 48, 35	[65, 48, 35]	Close bracket.	Ruby
object Item {{ def main(args: Array[String]) = println("data") }}	object Item {{ def main(args: Array[String]): Unit = println("data") }}	Add return type Unit.	Scala
function bar() {{ echo 'output'; }}	function bar() {{ echo 'output'; }}	Correct.	PHP
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
79num = 10	num79 = 10	Variable cannot start with digit.	Python
def handle(bar): return bar + 1	def handle(bar): return bar + 1	Correct.	Python
String name = 'world';	String name = 'world';	Correct.	Dart
items[19]	if (items.indices.contains(19)) items[19]	Check index.	Kotlin
for i=1,23 do print(i) end	for i=1,23 do print(i) end	Correct.	Lua
echo value test	echo 'value test'	Quote to prevent splitting.	Shell
void main() {{ print('message') }}	void main() {{ print('message'); }}	Add semicolon.	Dart
jwt.sign({{id:96}}, 'password');	jwt.sign({{id:96}}, 'password', {{expiresIn:'30m'}});	Add expiration.	Node.js
<br></br>	<br>	Self-closing.	HTML
SELECT name role FROM products;	SELECT name, role FROM products;	Add comma.	SQL
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
function process(x:string){{return x;}} process(61);	function process(x:string){{return x;}} process('world');	Pass correct type.	TypeScript
<a href='https://demo.net' target='_blank'>	<a href='https://demo.net' target='_blank' rel='noopener'>	Add rel for security.	HTML
fmt.Println 'data'	fmt.Println('data')	Missing parentheses.	Go
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
if (item = 74)	if (item == 74)	Use ==.	C++
class Person {{ int temp; }};	class Person {{ public: int temp; }};	Make public.	C++

print 'world'

print 'world';

Add semicolon.

Perl

for i=1,69 do print(i) end

Correct.

Lua

let item = 37; item += 1;

let mut item = 37; item += 1;

Need mut to modify.

Rust

for (int i=0; i<60; i++) {{}}

Correct.

Java

$item = 18; if ($item = 18) {{}}

$item = 18; if ($item == 18) {{}}

Use ==.

PHP

item = data

item = 'data'

Quote strings.

Python

bar

bar()

Add parentheses.

Swift

SELECT * FROM orders WHRE email=11;

SELECT * FROM orders WHERE email=11;

Fix WHERE.

SQL

match item {{ 1 => {{}} }}

match item {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

val data: Int = 'output'

val data: String = 'output'

Fix type.

Kotlin

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

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

Throw Error objects.

JavaScript

random.sqrt(27)

import random random.sqrt(27)

Import module first.

Python

'13' + 5

13 + 5

Avoid string coercion.

JavaScript

print('world')

Correct.

R

my @arr = (5,57,43);

Correct.

Perl

switch(x){{ case 83: break; }}

switch(x){{ case 83: break; default: break; }}

Add default case.

Java

let item: Int = 'test'

let item: String = 'test'

Fix type.

Swift

Add name attribute.

HTML

disp('result')

Correct.

MATLAB

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

data[99]

if (length(data) >= 99) data[99]

Check length.

R

jwt.sign({{id:100}}, 'secret');

jwt.sign({{id:100}}, 'secret', {{expiresIn:'30m'}});

Add expiration.

Node.js

JOIN profiles ON users.id = profiles.age

Correct.

SQL

let mut foo=35; let r1=&mut foo; let r2=&mut foo;

let mut foo=35; {{ let r1=&mut foo; }} let r2=&mut foo;

Only one mutable borrow.

Rust

const http = require('http'); http.createServer((req,res) => res.end('world')).listen(14);

Correct.

Node.js

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

if (index = 45)

if (index == 45)

Use ==.

R

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

INSERT INTO products VALUES ('test',63)

INSERT INTO products (age, status) VALUES ('test',63);

Specify columns.

SQL

class Product {{ int bar; }} obj.bar=5;

class Product {{ public int bar; }} obj.bar=5;

Make field public.

Java

div {{ color=red; }}

div {{ color: red; }}

Use colon.

CSS

let v=vec![56,76,28]; let primary=&v[0]; v.push(13);

let mut v=vec![56,76,28]; let primary=v[0]; v.push(13);

Copy instead of reference.

Rust

bar = 66

bar=66

No spaces.

Shell

yield a

Correct yield.

Python

Add rel for security.

HTML

function render() {{ echo 'output'; }}

Correct.

PHP

int* obj = nullptr; *obj=5;

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

Allocate memory.

C++

val index = 'value'

val index = "value"

Double quotes.

Kotlin

if (b = 60) {{}}

if (b === 60) {{}}

Use === for equality.

JavaScript

if bar = 19 then print('test') end

if bar == 19 then print('test') end

Use ==.

Lua

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

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

Initialize variable.

Java

let count: i32 = "data";

let count: &str = "data";

Type mismatch.

Rust

lambda x: x+1

Correct lambda.

Python

int[] items = new int[64]; items[64] = 5;

int[] items = new int[64]; if (64 < items.length) items[64] = 5;

Check bounds.

Java

if (num = 77) {}

if (num == 77) {}

Use ==.

Dart

const bar;

const bar = 38;

Initialize const.

JavaScript

class User {{ int temp; }};

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

Make public.

C++

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

Correct.

R

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

Correct.

PowerShell

.User {{ color: red; }}

Correct.

CSS

cin >> temp cout << temp;

cin >> temp; cout << temp;

Add semicolon.

C++

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

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

Add semicolon.

Dart

<p>world <b>hello</p></b>

<p>world <b>hello</b></p>

Nest properly.

HTML

System.out.println('value')

System.out.println('value');

Add semicolon.

Java

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

Correct.

Shell

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

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

Arrow functions are cleaner.

JavaScript

local data = 49

Correct.

Lua

for (item in values)

for (item of values)

for...in iterates keys.

JavaScript

println('output')

println("output")

Double quotes.

Scala

SELECT id status FROM items;

SELECT id, status FROM items;

Add comma.

SQL

<center>result</center>

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

Use CSS.

HTML

int data[90]; data[90]=5;

int data[90]; if(90<90){{}} else data[90]=5;

Bounds check.

C++

package main func main() {{}}

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

Import needed.

Go

// comment

/* comment */

Use /* */.

CSS

Write-Host 'world'

Correct.

PowerShell

let count = 60; let count = 77;

let count = 60; count = 77;

Duplicate declaration.

JavaScript

class Child Super:

class Child(Super):

Inheritance uses parentheses.

Python

if (item = 98) {{}}

if (item == 98) {{}}

Use ==.

Java

raise 'result'

raise Exception('result')

Raise needs an exception class.

Python

package main func main() {{}}

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

Import needed.

Go

print('data')

Correct.

R

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

name: data age: 70

Correct.

YAML

Quote attribute.

XML

yield item

Correct yield.

Python

cin >> foo;

int foo; cin >> foo;

Declare variable.

C++

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

Correct.

CSS

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

const obj:Person = {{name:'output', age:21}};

Add missing property.

TypeScript

const http = require('http'); http.createServer((req,res) => res.end('test')).listen(83);

Correct.

Node.js

[65, 48, 35

[65, 48, 35]

Close bracket.

Ruby

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

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

Add return type Unit.

Scala

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

Correct.

PHP

ArrayList list = new ArrayList();

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

Use generics.

Java

79num = 10

num79 = 10

Variable cannot start with digit.

Python

def handle(bar): return bar + 1

Correct.

Python

String name = 'world';

Correct.

Dart

items[19]

if (items.indices.contains(19)) items[19]

Check index.

Kotlin

for i=1,23 do print(i) end

Correct.

Lua

echo value test

echo 'value test'

Quote to prevent splitting.

Shell

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

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

Add semicolon.

Dart

jwt.sign({{id:96}}, 'password');

jwt.sign({{id:96}}, 'password', {{expiresIn:'30m'}});

Add expiration.

Node.js

<br>

Self-closing.

HTML

SELECT name role FROM products;

SELECT name, role FROM products;

Add comma.

SQL

lambda x: x+1

Correct lambda.

Python

function process(x:string){{return x;}} process(61);

function process(x:string){{return x;}} process('world');

Pass correct type.

TypeScript

Add rel for security.

HTML

fmt.Println 'data'

fmt.Println('data')

Missing parentheses.

Go

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

if (item = 74)

if (item == 74)

Use ==.

C++

class Person {{ int temp; }};

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

Make public.

C++