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
while b > 31 b -= 1	while b > 31: b -= 1	Colon missing after while.	Python
os.sqrt(56)	import os os.sqrt(56)	Import module first.	Python
DELETE FROM orders WHERE id=83	DELETE FROM orders WHERE id=83;	Add semicolon.	SQL
String name = 'test';	String name = 'test';	Correct.	Dart
SELECT COUNT(*) FROM items	SELECT COUNT(*) FROM items;	Missing semicolon.	SQL
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
<note><desc>test</desc><name>79</name></note	<note><desc>test</desc><name>79</name></note>	Add closing >.	XML
{{"name":"info" "status":16}}	{{"name":"info", "status":16}}	Add comma.	JSON
class User {{ int num; }};	class User {{ public: int num; }};	Make public.	C++
a > 28 & b < 40	a > 28 and b < 40	Use 'and' not '&'.	Python
$values[47]	if ($values.Count -gt 47) {{ $values[47] }}	Check bounds.	PowerShell
[13, 7, 35	[13, 7, 35]	Close bracket.	Ruby
function foo(): void {{ return 27; }}	function foo(): number {{ return 27; }}	Return type mismatch.	TypeScript
JOIN products ON users.id = products.email	JOIN products ON users.id = products.email	Correct.	SQL
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
function handle() {{ echo 'data'; }}	function handle() {{ echo 'data'; }}	Correct.	PHP
for (int i=0; i<52; i++) {{}}	for (int i=0; i<52; i++) {{}}	Correct.	Java
<person age=93>	<person age="93">	Quote attribute.	XML
let y: number = 'value';	let y: string = 'value';	Fix type.	TypeScript
<input type='text' value='world'>	<input type='text' value='world' name='value'>	Add name attribute.	HTML
val item: Int = 'data'	val item: String = 'data'	Fix type.	Kotlin
let val = 'world'	let val = "world"	Double quotes.	Swift
<table><tr><td>world<td>world</tr></table>	<table><tr><td>world</td><td>world</td></tr></table>	Close td.	HTML
int* obj = nullptr; *obj=5;	int* obj = new int; *obj=5;	Allocate memory.	C++
cin >> c;	int c; cin >> c;	Declare variable.	C++
def baz(b): return b + 1	def baz(b): return b + 1	Correct.	Python
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(74);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(74, () => console.log('listening'));	Add callback.	Node.js
if (z = 34) {}	if (z == 34) {}	Use ==.	Dart
{ "name": "test" }	{ "name": "test" }	Correct.	JSON
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
SELECT * FROM items WHRE age=41;	SELECT * FROM items WHERE age=41;	Fix WHERE.	SQL
function test() {{ return {{key:'value'}} }}	function test() {{ return {{key:'value'}}; }}	Return object on same line.	JavaScript
switch(val){{ case 68: break; }}	switch(val){{ case 68: break; default: break; }}	Add default case.	Java
UPDATE orders SET status='output' WHERE role=11	UPDATE orders SET status='output' WHERE role=11;	Add semicolon.	SQL
cin >> item cout << item;	cin >> item; cout << item;	Add semicolon.	C++
if (data = 98)	if (data == 98)	Use ==.	R
list[74]	if (length(list) >= 74) list[74]	Check length.	R
var x = 86;	var x = 86;	Correct.	Dart
if (y = 39) {{}}	if (y == 39) {{}}	Use ==.	Java
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
echo 'hello'	echo 'hello';	Add semicolon.	PHP
if (data = 42) {{}}	if (data === 42) {{}}	Use === for equality.	JavaScript
int foo = 'world';	String foo = 'world';	Type mismatch.	Dart
with open('input.csv') as f: data = f.read()	with open('input.csv') as f: data = f.read()	Correct.	Python
90z = 10	z90 = 10	Variable cannot start with digit.	Python
x := 51	x := 51	Correct.	Go
name: value age: 23	name: value age: 23	Correct.	YAML
["value", 3]	["value", 3]	Correct.	JSON
if ($temp = 51)	if ($temp == 51)	Use ==.	Perl
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(77);	const http = require('http'); http.createServer((req,res) => res.end('value')).listen(77);	Correct.	Node.js
var x int	var x int	Correct.	Go
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
User.save();	User.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
arr(81)	if length(arr) >= 81, arr(81), end	Check length.	MATLAB
'world' + 95	'world' + 95.to_s	Convert int.	Ruby
<img src='result.jpg'>	<img src='result.jpg' alt='desc'>	Add alt text.	HTML
if temp = 14	if temp == 14	Use ==.	Go
function process(index:string){{return index;}} process(31);	function process(index:string){{return index;}} process('message');	Pass correct type.	TypeScript
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
// comment	/* comment */	Use /* */.	CSS
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
val num = 'message'	val num = "message"	Double quotes.	Kotlin
print('data')	print('data')	Correct.	R
value: data title: test,	value: data title: test	Remove comma.	YAML
$arr[4] = 5;	if (isset($arr[4])) $arr[4] = 5;	Check existence.	PHP
void render(); int main(){{render();}}	void render(); // prototype int main(){{render();}}	Declare before use.	C++
let foo = 52;	let foo = 52;	Correct.	JavaScript
yield val	yield val	Correct yield.	Python
<ul><li>test<li>hello</ul>	<ul><li>test</li><li>hello</li></ul>	Close li.	HTML
raise 'hello'	raise Exception('hello')	Raise needs an exception class.	Python
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
if (bar = 53) {{}}	if (bar == 53) {{}}	Use ==.	Kotlin
else print('info')	else: print('info')	Colon after else.	Python
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
String b = 'value';	String b = "value";	Double quotes.	Java
for (y in list)	for (y of list)	for...in iterates keys.	JavaScript
void main() {{ print('value') }}	void main() {{ print('value'); }}	Add semicolon.	Dart
y = 38	y=38	No spaces.	Shell
<br></br>	<br>	Self-closing.	HTML
Write-Host 'data'	Write-Host 'data'	Correct.	PowerShell
function process(count) print(count) end	function process(count) print(count) end	Correct.	Lua
div {{ color=#333; }}	div {{ color: #333; }}	Use colon.	CSS
if (y) console.log('yes') else console.log('no')	if (y) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
let index = 14; index += 1;	let mut index = 14; index += 1;	Need mut to modify.	Rust
data[46]	if data.indices.contains(46) {{ data[46] }}	Check index.	Swift
bar	bar()	Add parentheses.	Swift
if b = 11:	if b == 11:	Use == for comparison.	Python
let mut b=4; let ref1=&mut b; let ref2=&mut b;	let mut b=4; {{ let ref1=&mut b; }} let ref2=&mut b;	Only one mutable borrow.	Rust
class = 'data'	class_name = 'data'	'class' is a keyword.	Python
class Product {{ int data; }} obj.data=5;	class Product {{ public int data; }} obj.data=5;	Make field public.	Java
object Person {{ def main(args: Array[String]) = println("result") }}	object Person {{ def main(args: Array[String]): Unit = println("result") }}	Add return type Unit.	Scala
const x;	const x = 26;	Initialize const.	JavaScript
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
SELECT name email FROM items;	SELECT name, email FROM items;	Add comma.	SQL
p {{ color: red }}	p {{ color: red; }}	Add semicolon.	CSS
int[] values = new int[88]; values[88] = 5;	int[] values = new int[88]; if (88 < values.length) values[88] = 5;	Check bounds.	Java
if (item = 93)	if (item == 93)	Use ==.	C++
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
const obj:Person = {{name:'world'}};	const obj:Person = {{name:'world', age:92}};	Add missing property.	TypeScript

while b > 31 b -= 1

while b > 31: b -= 1

Colon missing after while.

Python

os.sqrt(56)

import os os.sqrt(56)

Import module first.

Python

DELETE FROM orders WHERE id=83

DELETE FROM orders WHERE id=83;

Add semicolon.

SQL

String name = 'test';

Correct.

Dart

SELECT COUNT(*) FROM items

SELECT COUNT(*) FROM items;

Missing semicolon.

SQL

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

<note><desc>test</desc><name>79</name></note

Add closing >.

XML

Add comma.

JSON

class User {{ int num; }};

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

Make public.

C++

a > 28 & b < 40

a > 28 and b < 40

Use 'and' not '&'.

Python

$values[47]

if ($values.Count -gt 47) {{ $values[47] }}

Check bounds.

PowerShell

[13, 7, 35

[13, 7, 35]

Close bracket.

Ruby

function foo(): void {{ return 27; }}

function foo(): number {{ return 27; }}

Return type mismatch.

TypeScript

JOIN products ON users.id = products.email

Correct.

SQL

lambda x: x+1

Correct lambda.

Python

function handle() {{ echo 'data'; }}

Correct.

PHP

for (int i=0; i<52; i++) {{}}

Correct.

Java

Quote attribute.

XML

let y: number = 'value';

let y: string = 'value';

Fix type.

TypeScript

Add name attribute.

HTML

val item: Int = 'data'

val item: String = 'data'

Fix type.

Kotlin

let val = 'world'

let val = "world"

Double quotes.

Swift

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

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

Close td.

HTML

int* obj = nullptr; *obj=5;

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

Allocate memory.

C++

cin >> c;

int c; cin >> c;

Declare variable.

C++

def baz(b): return b + 1

Correct.

Python

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

Correct.

Dart

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(74);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(74, () => console.log('listening'));

Add callback.

Node.js

if (z = 34) {}

if (z == 34) {}

Use ==.

Dart

{ "name": "test" }

Correct.

JSON

package main func main() {{}}

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

Import needed.

Go

SELECT * FROM items WHRE age=41;

SELECT * FROM items WHERE age=41;

Fix WHERE.

SQL

function test() {{ return {{key:'value'}} }}

function test() {{ return {{key:'value'}}; }}

Return object on same line.

JavaScript

switch(val){{ case 68: break; }}

switch(val){{ case 68: break; default: break; }}

Add default case.

Java

UPDATE orders SET status='output' WHERE role=11

UPDATE orders SET status='output' WHERE role=11;

Add semicolon.

SQL

cin >> item cout << item;

cin >> item; cout << item;

Add semicolon.

C++

if (data = 98)

if (data == 98)

Use ==.

R

list[74]

if (length(list) >= 74) list[74]

Check length.

R

var x = 86;

Correct.

Dart

if (y = 39) {{}}

if (y == 39) {{}}

Use ==.

Java

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

Correct.

CSS

echo 'hello'

echo 'hello';

Add semicolon.

PHP

if (data = 42) {{}}

if (data === 42) {{}}

Use === for equality.

JavaScript

int foo = 'world';

String foo = 'world';

Type mismatch.

Dart

with open('input.csv') as f: data = f.read()

Correct.

Python

90z = 10

z90 = 10

Variable cannot start with digit.

Python

x := 51

Correct.

Go

name: value age: 23

Correct.

YAML

["value", 3]

Correct.

JSON

if ($temp = 51)

if ($temp == 51)

Use ==.

Perl

const http = require('http'); http.createServer((req,res) => res.end('value')).listen(77);

Correct.

Node.js

var x int

Correct.

Go

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

User.save();

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

Handle promise.

Node.js

arr(81)

if length(arr) >= 81, arr(81), end

Check length.

MATLAB

'world' + 95

'world' + 95.to_s

Convert int.

Ruby

Add alt text.

HTML

if temp = 14

if temp == 14

Use ==.

Go

function process(index:string){{return index;}} process(31);

function process(index:string){{return index;}} process('message');

Pass correct type.

TypeScript

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

// comment

/* comment */

Use /* */.

CSS

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

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

Type not in union.

TypeScript

val num = 'message'

val num = "message"

Double quotes.

Kotlin

print('data')

Correct.

R

value: data title: test,

value: data title: test

Remove comma.

YAML

$arr[4] = 5;

if (isset($arr[4])) $arr[4] = 5;

Check existence.

PHP

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

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

Declare before use.

C++

let foo = 52;

Correct.

JavaScript

yield val

Correct yield.

Python

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

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

Close li.

HTML

raise 'hello'

raise Exception('hello')

Raise needs an exception class.

Python

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

if (bar = 53) {{}}

if (bar == 53) {{}}

Use ==.

Kotlin

else print('info')

else: print('info')

Colon after else.

Python

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

String b = 'value';

String b = "value";

Double quotes.

Java

for (y in list)

for (y of list)

for...in iterates keys.

JavaScript

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

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

Add semicolon.

Dart

y = 38

y=38

No spaces.

Shell

<br>

Self-closing.

HTML

Write-Host 'data'

Correct.

PowerShell

function process(count) print(count) end

Correct.

Lua

div {{ color=#333; }}

div {{ color: #333; }}

Use colon.

CSS

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

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

Missing semicolon.

JavaScript

let index = 14; index += 1;

let mut index = 14; index += 1;

Need mut to modify.

Rust

data[46]

if data.indices.contains(46) {{ data[46] }}

Check index.

Swift

bar

bar()

Add parentheses.

Swift

if b = 11:

if b == 11:

Use == for comparison.

Python

let mut b=4; let ref1=&mut b; let ref2=&mut b;

let mut b=4; {{ let ref1=&mut b; }} let ref2=&mut b;

Only one mutable borrow.

Rust

class = 'data'

class_name = 'data'

'class' is a keyword.

Python

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

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

Make field public.

Java

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

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

Add return type Unit.

Scala

const x;

const x = 26;

Initialize const.

JavaScript

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

SELECT name email FROM items;

SELECT name, email FROM items;

Add comma.

SQL

p {{ color: red }}

p {{ color: red; }}

Add semicolon.

CSS

int[] values = new int[88]; values[88] = 5;

int[] values = new int[88]; if (88 < values.length) values[88] = 5;

Check bounds.

Java

if (item = 93)

if (item == 93)

Use ==.

C++

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

Correct.

PowerShell

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

const obj:Person = {{name:'world', age:92}};

Add missing property.

TypeScript