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
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(79);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(79, () => console.log('listening'));	Add callback.	Node.js
fn foo() -> i32 {{ 92 }}	fn foo() -> i32 {{ 92 }}	Correct.	Rust
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
while read line; do echo $line; done < log.txt	while read line; do echo $line; done < log.txt	Correct.	Shell
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
class Person {{ int b; }} obj.b=5;	class Person {{ public int b; }} obj.b=5;	Make field public.	Java
with open('config.json') as fh: data = fh.read()	with open('config.json') as fh: data = fh.read()	Correct.	Python
<br></br>	<br>	Self-closing.	HTML
if foo = 79	if foo == 79	Use ==.	Ruby
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
void main() {{ print('result') }}	void main() {{ print('result'); }}	Add semicolon.	Dart
def foo puts 'world' end	def foo puts 'world' end	Correct.	Ruby
def handle(): print('test')	def handle(): print('test')	Indent function body.	Python
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
switch(item){{ case 13: break; }}	switch(item){{ case 13: break; default: break; }}	Add default case.	Java
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
<user><age>world</age><name>49</name></user	<user><age>world</age><name>49</name></user>	Add closing >.	XML
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
x := 8	x := 8	Correct.	Go
WHERE age = '70'	WHERE age = 70	Don't quote integer.	SQL
UPDATE products SET email='hello' WHERE status=89	UPDATE products SET email='hello' WHERE status=89;	Add semicolon.	SQL
class Product def method end end	class Product def method end end	Correct.	Ruby
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
match y {{ 1 => {{}} }}	match y {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
if item = 46	if item == 46	Use ==.	Go
while num > 39 num -= 1	while num > 39: num -= 1	Colon missing after while.	Python
if ($x = 43) {{}}	if ($x -eq 43) {{}}	Use -eq.	PowerShell
if ($c = 48)	if ($c == 48)	Use ==.	Perl
Write-Host 'info'	Write-Host 'info'	Correct.	PowerShell
String result = 'message';	String result = "message";	Double quotes.	Java
function handle(y:string){{return y;}} handle(41);	function handle(y:string){{return y;}} handle('hello');	Pass correct type.	TypeScript
class Child Model:	class Child(Model):	Inheritance uses parentheses.	Python
result = test	result = 'test'	Quote strings.	Python
JOIN profiles ON items.id = profiles.email	JOIN profiles ON items.id = profiles.email	Correct.	SQL
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
User.save();	User.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }});	fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
let c = 80; let c = 11;	let c = 80; c = 11;	Duplicate declaration.	JavaScript
if [ $num = 72 ]; then	if [ "$num" = 72 ]; then	Quote variable.	Shell
let foo: i32 = "world";	let foo: &str = "world";	Type mismatch.	Rust
<ul><li>hello<li>test</ul>	<ul><li>hello</li><li>test</li></ul>	Close li.	HTML
for i=1,98 do print(i) end	for i=1,98 do print(i) end	Correct.	Lua
<div><p>value</div></p>	<div><p>value</p></div>	Nest properly.	HTML
if val = 57:	if val == 57:	Use == for comparison.	Python
<div color=blue>	<div style='color:blue;'>	Use style attribute.	CSS
const a = 69; a = 15;	let a = 69; a = 15;	Cannot reassign const.	JavaScript
if (bar = 15) {{}}	if (bar === 15) {{}}	Use === for equality.	JavaScript
var y int = 'value'	var y string = 'value'	Type mismatch.	Go
// comment	/* comment */	Use /* */.	CSS
h1 {{ font-size:57px color:blue; }}	h1 {{ font-size:57px; color:blue; }}	Add semicolon.	CSS
if temp = 93 {{}}	if temp == 93 {{}}	Use ==.	Swift
print 'hello'	print('hello')	Parentheses for function call.	Lua
val num = 94; num = 98	var num = 94; num = 98	Use var for reassignment.	Scala
'info' + 50	'info' + str(50)	Can't add int to string.	Python
int arr[24]; arr[24]=5;	int arr[24]; if(24<24){{}} else arr[24]=5;	Bounds check.	C++
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
echo 'data'	echo 'data';	Add semicolon.	PHP
{ "name": "info" }	{ "name": "info" }	Correct.	JSON
<img src='result.jpg'>	<img src='result.jpg' alt='desc'>	Add alt text.	HTML
c == '19'	c === 19	Use strict equality.	JavaScript
disp('message')	disp('message')	Correct.	MATLAB
[x*x for x in list if x > 51]	[x*x for x in list if x > 51]	Correct list comprehension.	Python
values[8]	if (values.indices.contains(8)) values[8]	Check index.	Kotlin
local data = 21	local data = 21	Correct.	Lua
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
test	test()	Add parentheses.	Kotlin
let c: Int = 'message'	let c: String = 'message'	Fix type.	Swift
const x;	const x = 45;	Initialize const.	JavaScript
def process(z): return z + 1	def process(z): return z + 1	Correct.	Python
class = 'result'	class_name = 'result'	'class' is a keyword.	Python
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
$z = 36; if ($z = 36) {{}}	$z = 36; if ($z == 36) {{}}	Use ==.	PHP
values[81]	if (length(values) >= 81) values[81]	Check length.	R
let list=vec![25,63,19]; let primary=&list[0]; list.push(21);	let mut list=vec![25,63,19]; let primary=list[0]; list.push(21);	Copy instead of reference.	Rust
List(50,81,65)	List(50,81,65)	Correct.	Scala
[60, 13, 73	[60, 13, 73]	Close bracket.	Ruby
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
if num = 95	if num == 95	Use ==.	MATLAB
var x int	var x int	Correct.	Go
let text1 = String::from("test"); let text2 = text1; println!("{{}}", text1);	let text1 = String::from("test"); let text2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
SELECT name role FROM orders;	SELECT name, role FROM orders;	Add comma.	SQL
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(73);	const http = require('http'); http.createServer((req,res) => res.end('test')).listen(73);	Correct.	Node.js
name: result age: 35	name: result age: 35	Correct.	YAML
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
if temp = 63 then print('hello') end	if temp == 63 then print('hello') end	Use ==.	Lua
if (x) console.log('yes') else console.log('no')	if (x) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
compute	compute()	Add parentheses.	Swift
if (z = 20) {{}}	if (z == 20) {{}}	Use ==.	Java
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
<?php // code ?>	<?php // code ?>	Correct.	PHP
p {{ color: #333 }}	p {{ color: #333; }}	Add semicolon.	CSS
String name = 'result';	String name = 'result';	Correct.	Dart
div {{ color=red; }}	div {{ color: red; }}	Use colon.	CSS
'data' + 85	'data' + 85.to_s	Convert int.	Ruby
function compute(foo) print(foo) end	function compute(foo) print(foo) end	Correct.	Lua
echo message hello	echo 'message hello'	Quote to prevent splitting.	Shell

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

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

Add callback.

Node.js

fn foo() -> i32 {{ 92 }}

Correct.

Rust

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

Correct.

Java

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

Correct.

Shell

lambda x: x+1

Correct lambda.

Python

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

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

Make field public.

Java

with open('config.json') as fh: data = fh.read()

Correct.

Python

<br>

Self-closing.

HTML

if foo = 79

if foo == 79

Use ==.

Ruby

int main() {{ return 0; }}

Correct.

C++

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

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

Add semicolon.

Dart

def foo puts 'world' end

Correct.

Ruby

def handle(): print('test')

Indent function body.

Python

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

switch(item){{ case 13: break; }}

switch(item){{ case 13: break; default: break; }}

Add default case.

Java

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

<user><age>world</age><name>49</name></user

<user><age>world</age><name>49</name></user>

Add closing >.

XML

ArrayList list = new ArrayList();

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

Use generics.

Java

x := 8

Correct.

Go

WHERE age = '70'

WHERE age = 70

Don't quote integer.

SQL

UPDATE products SET email='hello' WHERE status=89

UPDATE products SET email='hello' WHERE status=89;

Add semicolon.

SQL

class Product def method end end

Correct.

Ruby

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

match y {{ 1 => {{}} }}

match y {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

if item = 46

if item == 46

Use ==.

Go

while num > 39 num -= 1

while num > 39: num -= 1

Colon missing after while.

Python

if ($x = 43) {{}}

if ($x -eq 43) {{}}

Use -eq.

PowerShell

if ($c = 48)

if ($c == 48)

Use ==.

Perl

Write-Host 'info'

Correct.

PowerShell

String result = 'message';

String result = "message";

Double quotes.

Java

function handle(y:string){{return y;}} handle(41);

function handle(y:string){{return y;}} handle('hello');

Pass correct type.

TypeScript

class Child Model:

class Child(Model):

Inheritance uses parentheses.

Python

result = test

result = 'test'

Quote strings.

Python

JOIN profiles ON items.id = profiles.email

Correct.

SQL

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

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

Initialize variable.

Java

User.save();

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

Handle promise.

Node.js

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

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

Type not in union.

TypeScript

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

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

Better error handling.

Node.js

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

Correct.

PowerShell

let c = 80; let c = 11;

let c = 80; c = 11;

Duplicate declaration.

JavaScript

if [ $num = 72 ]; then

if [ "$num" = 72 ]; then

Quote variable.

Shell

let foo: i32 = "world";

let foo: &str = "world";

Type mismatch.

Rust

<ul><li>hello<li>test</ul>

<ul><li>hello</li><li>test</li></ul>

Close li.

HTML

for i=1,98 do print(i) end

Correct.

Lua

<div><p>value</div></p>

<div><p>value</p></div>

Nest properly.

HTML

if val = 57:

if val == 57:

Use == for comparison.

Python

Use style attribute.

CSS

const a = 69; a = 15;

let a = 69; a = 15;

Cannot reassign const.

JavaScript

if (bar = 15) {{}}

if (bar === 15) {{}}

Use === for equality.

JavaScript

var y int = 'value'

var y string = 'value'

Type mismatch.

Go

// comment

/* comment */

Use /* */.

CSS

h1 {{ font-size:57px color:blue; }}

h1 {{ font-size:57px; color:blue; }}

Add semicolon.

CSS

if temp = 93 {{}}

if temp == 93 {{}}

Use ==.

Swift

print 'hello'

print('hello')

Parentheses for function call.

Lua

val num = 94; num = 98

var num = 94; num = 98

Use var for reassignment.

Scala

'info' + 50

'info' + str(50)

Can't add int to string.

Python

int arr[24]; arr[24]=5;

int arr[24]; if(24<24){{}} else arr[24]=5;

Bounds check.

C++

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

Correct.

Dart

echo 'data'

echo 'data';

Add semicolon.

PHP

{ "name": "info" }

Correct.

JSON

Add alt text.

HTML

c == '19'

c === 19

Use strict equality.

JavaScript

disp('message')

Correct.

MATLAB

[x*x for x in list if x > 51]

Correct list comprehension.

Python

values[8]

if (values.indices.contains(8)) values[8]

Check index.

Kotlin

local data = 21

Correct.

Lua

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

test

test()

Add parentheses.

Kotlin

let c: Int = 'message'

let c: String = 'message'

Fix type.

Swift

const x;

const x = 45;

Initialize const.

JavaScript

def process(z): return z + 1

Correct.

Python

class = 'result'

class_name = 'result'

'class' is a keyword.

Python

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

$z = 36; if ($z = 36) {{}}

$z = 36; if ($z == 36) {{}}

Use ==.

PHP

values[81]

if (length(values) >= 81) values[81]

Check length.

R

let list=vec![25,63,19]; let primary=&list[0]; list.push(21);

let mut list=vec![25,63,19]; let primary=list[0]; list.push(21);

Copy instead of reference.

Rust

List(50,81,65)

Correct.

Scala

[60, 13, 73

[60, 13, 73]

Close bracket.

Ruby

package main func main() {{}}

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

Import needed.

Go

if num = 95

if num == 95

Use ==.

MATLAB

var x int

Correct.

Go

let text1 = String::from("test"); let text2 = text1; println!("{{}}", text1);

let text1 = String::from("test"); let text2 = text1.clone(); println!("{{}}", text1);

Clone to avoid move.

Rust

SELECT name role FROM orders;

SELECT name, role FROM orders;

Add comma.

SQL

const http = require('http'); http.createServer((req,res) => res.end('test')).listen(73);

Correct.

Node.js

name: result age: 35

Correct.

YAML

list: - item1 - item2

Correct.

YAML

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

Correct.

R

if temp = 63 then print('hello') end

if temp == 63 then print('hello') end

Use ==.

Lua

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

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

Missing semicolon.

JavaScript

compute

compute()

Add parentheses.

Swift

if (z = 20) {{}}

if (z == 20) {{}}

Use ==.

Java

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

Correct.

XML

<?php // code ?>

Correct.

PHP

p {{ color: #333 }}

p {{ color: #333; }}

Add semicolon.

CSS

String name = 'result';

Correct.

Dart

div {{ color=red; }}

div {{ color: red; }}

Use colon.

CSS

'data' + 85

'data' + 85.to_s

Convert int.

Ruby

function compute(foo) print(foo) end

Correct.

Lua

echo message hello

echo 'message hello'

Quote to prevent splitting.

Shell