Corpus-NZ/Code-Syntax-Expanded · Data Studio

wrong_code stringlengths 3 123	correct_code stringlengths 3 155	explanation stringclasses 101 values	language stringclasses 26 values
sys.sqrt(18)	import sys sys.sqrt(18)	Import module first.	Python
let result = 11;	let result = 11;	Correct.	JavaScript
<person age=79>	<person age="79">	Quote attribute.	XML
JOIN orders ON items.id = orders.name	JOIN orders ON items.id = orders.name	Correct.	SQL
class = 'info'	class_name = 'info'	'class' is a keyword.	Python
if (foo = 33) {}	if (foo == 33) {}	Use ==.	Dart
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
for (data in arr)	for (data of arr)	for...in iterates keys.	JavaScript
SELECT * FROM items WHRE id=94;	SELECT * FROM items WHERE id=94;	Fix WHERE.	SQL
cin >> z;	int z; cin >> z;	Declare variable.	C++
'value' + 80	'value' + str(80)	Can't add int to string.	Python
if (b = 59)	if (b == 59)	Use ==.	R
val == '97'	val === 97	Use strict equality.	JavaScript
var x int	var x int	Correct.	Go
raise 'info'	raise Exception('info')	Raise needs an exception class.	Python
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
String name = 'message';	String name = 'message';	Correct.	Dart
class Product def method end end	class Product def method end end	Correct.	Ruby
<input type='text' value='hello'>	<input type='text' value='hello' name='title'>	Add name attribute.	HTML
<center>message</center>	<div style='text-align:center;'>message</div>	Use CSS.	HTML
$items[81]	if ($items.Count -gt 81) {{ $items[81] }}	Check bounds.	PowerShell
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
arr(11)	if length(arr) >= 11, arr(11), end	Check length.	MATLAB
<?php // code ?>	<?php // code ?>	Correct.	PHP
baz	baz()	Add parentheses.	Kotlin
if z = 43	if z == 43	Use ==.	Go
let temp: number = 'value';	let temp: string = 'value';	Fix type.	TypeScript
with open('input.csv') as fh: data = fh.read()	with open('input.csv') as fh: data = fh.read()	Correct.	Python
if temp = 30	if temp == 30	Use ==.	Ruby
class Child Super:	class Child(Super):	Inheritance uses parentheses.	Python
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(97);	const http = require('http'); http.createServer((req,res) => res.end('test')).listen(97);	Correct.	Node.js
["test", 55]	["test", 55]	Correct.	JSON
print 'hello'	print('hello')	print needs parentheses.	Python
let s1 = String::from("data"); let str2 = s1; println!("{{}}", s1);	let s1 = String::from("data"); let str2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
if (num = 56) {{}}	if (num == 56) {{}}	Use ==.	Java
y > 21 & b < 85	y > 21 and b < 85	Use 'and' not '&'.	Python
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
INSERT INTO orders VALUES ('hello',9)	INSERT INTO orders (age, email) VALUES ('hello',9);	Specify columns.	SQL
const obj:Person = {{name:'hello'}};	const obj:Person = {{name:'hello', age:91}};	Add missing property.	TypeScript
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
// comment	/* comment */	Use /* */.	CSS
echo hello hello	echo 'hello hello'	Quote to prevent splitting.	Shell
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
if ($result = 74)	if ($result == 74)	Use ==.	Perl
String item = 'result';	String item = "result";	Double quotes.	Java
function test(count) print(count) end	function test(count) print(count) end	Correct.	Lua
function compute(): void {{ return 64; }}	function compute(): number {{ return 64; }}	Return type mismatch.	TypeScript
div {{ color=blue; }}	div {{ color: blue; }}	Use colon.	CSS
if c > 28 print('test')	if c > 28: print('test')	Colon missing after if.	Python
int[] arr = new int[31]; arr[31] = 5;	int[] arr = new int[31]; if (31 < arr.length) arr[31] = 5;	Check bounds.	Java
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
const count = 11; count = 95;	let count = 11; count = 95;	Cannot reassign const.	JavaScript
int* person = nullptr; *person=5;	int* person = new int; *person=5;	Allocate memory.	C++
if (a = 33) {{}}	if (a == 33) {{}}	Use ==.	Kotlin
DELETE FROM items WHERE email=29	DELETE FROM items WHERE email=29;	Add semicolon.	SQL
const a;	const a = 42;	Initialize const.	JavaScript
if x = 68 {{}}	if x == 68 {{}}	Use ==.	Swift
print('test')	print('test')	Correct.	R
'29' + 10	29 + 10	Avoid string coercion.	JavaScript
h1 {{ font-size:54px color:green; }}	h1 {{ font-size:54px; color:green; }}	Add semicolon.	CSS
int items[55]; items[55]=5;	int items[55]; if(55<55){{}} else items[55]=5;	Bounds check.	C++
<div><p>hello</div></p>	<div><p>hello</p></div>	Nest properly.	HTML
$y = 99; if ($y = 99) {{}}	$y = 99; if ($y == 99) {{}}	Use ==.	PHP
print 'info'	print 'info';	Add semicolon.	Perl
<div color=blue>	<div style='color:blue;'>	Use style attribute.	CSS
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
items[83]	if (length(items) >= 83) items[83]	Check length.	R
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
Write-Host 'data'	Write-Host 'data'	Correct.	PowerShell
<img src='data.jpg'>	<img src='data.jpg' alt='desc'>	Add alt text.	HTML
match z {{ 1 => {{}} }}	match z {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
var index int = 'test'	var index string = 'test'	Type mismatch.	Go
val bar: Int = 'output'	val bar: String = 'output'	Fix type.	Kotlin
try {{ throw 'world'; }} catch(e) {{}}	try {{ throw new Error('world'); }} catch(e) {{}}	Throw Error objects.	JavaScript
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }});	fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
class Person {{ int x; }} obj.x=5;	class Person {{ public int x; }} obj.x=5;	Make field public.	Java
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
p {{ color: #fff }}	p {{ color: #fff; }}	Add semicolon.	CSS
<person name='value'/>	<person name="value"/>	Double quotes.	XML
local c = 40	local c = 40	Correct.	Lua
'data' + 52	'data' + 52.to_s	Convert int.	Ruby
def baz(): print('message')	def baz(): print('message')	Indent function body.	Python
print 'hello'	print('hello')	Parentheses for function call.	Lua
{{"title":"hello" "value":92}}	{{"title":"hello", "value":92}}	Add comma.	JSON
<br></br>	<br>	Self-closing.	HTML
jwt.sign({{id:68}}, 'token');	jwt.sign({{id:68}}, 'token', {{expiresIn:'15m'}});	Add expiration.	Node.js
SELECT age email FROM items;	SELECT age, email FROM items;	Add comma.	SQL
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
<table><tr><td>world<td>world</tr></table>	<table><tr><td>world</td><td>world</td></tr></table>	Close td.	HTML
my @arr = (22,19,34);	my @arr = (22,19,34);	Correct.	Perl
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
data.forEach(function(index) {{ console.log(index); }})	data.forEach((index) => {{ console.log(index); }})	Arrow functions are cleaner.	JavaScript
object User {{ def main(args: Array[String]) = println("result") }}	object User {{ def main(args: Array[String]): Unit = println("result") }}	Add return type Unit.	Scala
let a: number \| null = null; a.toFixed(76);	let a: number \| null = null; if(a!==null) a.toFixed(76);	Null check.	TypeScript
for (int i=0; i<71; i++) {{}}	for (int i=0; i<71; i++) {{}}	Correct.	Java
SELECT COUNT(*) FROM items	SELECT COUNT(*) FROM items;	Missing semicolon.	SQL
<person><age>message</age><desc>71</desc></person	<person><age>message</age><desc>71</desc></person>	Add closing >.	XML

sys.sqrt(18)

import sys sys.sqrt(18)

Import module first.

Python

let result = 11;

Correct.

JavaScript

Quote attribute.

XML

JOIN orders ON items.id = orders.name

Correct.

SQL

class = 'info'

class_name = 'info'

'class' is a keyword.

Python

if (foo = 33) {}

if (foo == 33) {}

Use ==.

Dart

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

for (data in arr)

for (data of arr)

for...in iterates keys.

JavaScript

SELECT * FROM items WHRE id=94;

SELECT * FROM items WHERE id=94;

Fix WHERE.

SQL

cin >> z;

int z; cin >> z;

Declare variable.

C++

'value' + 80

'value' + str(80)

Can't add int to string.

Python

if (b = 59)

if (b == 59)

Use ==.

R

val == '97'

val === 97

Use strict equality.

JavaScript

var x int

Correct.

Go

raise 'info'

raise Exception('info')

Raise needs an exception class.

Python

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

String name = 'message';

Correct.

Dart

class Product def method end end

Correct.

Ruby

Add name attribute.

HTML

<center>message</center>

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

Use CSS.

HTML

$items[81]

if ($items.Count -gt 81) {{ $items[81] }}

Check bounds.

PowerShell

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

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

Type not in union.

TypeScript

arr(11)

if length(arr) >= 11, arr(11), end

Check length.

MATLAB

<?php // code ?>

Correct.

PHP

baz

baz()

Add parentheses.

Kotlin

if z = 43

if z == 43

Use ==.

Go

let temp: number = 'value';

let temp: string = 'value';

Fix type.

TypeScript

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

Correct.

Python

if temp = 30

if temp == 30

Use ==.

Ruby

class Child Super:

class Child(Super):

Inheritance uses parentheses.

Python

const http = require('http'); http.createServer((req,res) => res.end('test')).listen(97);

Correct.

Node.js

["test", 55]

Correct.

JSON

print 'hello'

print('hello')

print needs parentheses.

Python

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

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

Clone to avoid move.

Rust

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

if (num = 56) {{}}

if (num == 56) {{}}

Use ==.

Java

y > 21 & b < 85

y > 21 and b < 85

Use 'and' not '&'.

Python

int main() {{ return 0; }}

Correct.

C++

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

Correct.

R

INSERT INTO orders VALUES ('hello',9)

INSERT INTO orders (age, email) VALUES ('hello',9);

Specify columns.

SQL

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

const obj:Person = {{name:'hello', age:91}};

Add missing property.

TypeScript

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

Correct.

PowerShell

// comment

/* comment */

Use /* */.

CSS

echo hello hello

echo 'hello hello'

Quote to prevent splitting.

Shell

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

Correct.

Java

if ($result = 74)

if ($result == 74)

Use ==.

Perl

String item = 'result';

String item = "result";

Double quotes.

Java

function test(count) print(count) end

Correct.

Lua

function compute(): void {{ return 64; }}

function compute(): number {{ return 64; }}

Return type mismatch.

TypeScript

div {{ color=blue; }}

div {{ color: blue; }}

Use colon.

CSS

if c > 28 print('test')

if c > 28: print('test')

Colon missing after if.

Python

int[] arr = new int[31]; arr[31] = 5;

int[] arr = new int[31]; if (31 < arr.length) arr[31] = 5;

Check bounds.

Java

Add rel for security.

HTML

const count = 11; count = 95;

let count = 11; count = 95;

Cannot reassign const.

JavaScript

int* person = nullptr; *person=5;

int* person = new int; *person=5;

Allocate memory.

C++

if (a = 33) {{}}

if (a == 33) {{}}

Use ==.

Kotlin

DELETE FROM items WHERE email=29

DELETE FROM items WHERE email=29;

Add semicolon.

SQL

const a;

const a = 42;

Initialize const.

JavaScript

if x = 68 {{}}

if x == 68 {{}}

Use ==.

Swift

print('test')

Correct.

R

'29' + 10

29 + 10

Avoid string coercion.

JavaScript

h1 {{ font-size:54px color:green; }}

h1 {{ font-size:54px; color:green; }}

Add semicolon.

CSS

int items[55]; items[55]=5;

int items[55]; if(55<55){{}} else items[55]=5;

Bounds check.

C++

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

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

Nest properly.

HTML

$y = 99; if ($y = 99) {{}}

$y = 99; if ($y == 99) {{}}

Use ==.

PHP

print 'info'

print 'info';

Add semicolon.

Perl

Use style attribute.

CSS

Correct.

XML

items[83]

if (length(items) >= 83) items[83]

Check length.

R

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

Write-Host 'data'

Correct.

PowerShell

Add alt text.

HTML

match z {{ 1 => {{}} }}

match z {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

var index int = 'test'

var index string = 'test'

Type mismatch.

Go

val bar: Int = 'output'

val bar: String = 'output'

Fix type.

Kotlin

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

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

Throw Error objects.

JavaScript

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

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

Better error handling.

Node.js

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

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

Make field public.

Java

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

Correct.

Shell

p {{ color: #fff }}

p {{ color: #fff; }}

Add semicolon.

CSS

Double quotes.

XML

local c = 40

Correct.

Lua

'data' + 52

'data' + 52.to_s

Convert int.

Ruby

def baz(): print('message')

Indent function body.

Python

print 'hello'

print('hello')

Parentheses for function call.

Lua

Add comma.

JSON

<br>

Self-closing.

HTML

jwt.sign({{id:68}}, 'token');

jwt.sign({{id:68}}, 'token', {{expiresIn:'15m'}});

Add expiration.

Node.js

SELECT age email FROM items;

SELECT age, email FROM items;

Add comma.

SQL

ArrayList list = new ArrayList();

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

Use generics.

Java

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

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

Close td.

HTML

my @arr = (22,19,34);

Correct.

Perl

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

Correct.

Shell

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

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

Arrow functions are cleaner.

JavaScript

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

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

Add return type Unit.

Scala

let a: number | null = null; a.toFixed(76);

let a: number | null = null; if(a!==null) a.toFixed(76);

Null check.

TypeScript

for (int i=0; i<71; i++) {{}}

Correct.

Java

SELECT COUNT(*) FROM items

SELECT COUNT(*) FROM items;

Missing semicolon.

SQL

<person><age>message</age><desc>71</desc></person

<person><age>message</age><desc>71</desc></person>

Add closing >.

XML