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
if (y = 65) {{}}	if (y === 65) {{}}	Use === for equality.	JavaScript
DELETE FROM orders WHERE status=3	DELETE FROM orders WHERE status=3;	Add semicolon.	SQL
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
if count = 10 then print('data') end	if count == 10 then print('data') end	Use ==.	Lua
for item in range(49) print(item)	for item in range(49): print(item)	Colon after for.	Python
<div color=#333>	<div style='color:#333;'>	Use style attribute.	CSS
if (index = 17)	if (index == 17)	Use ==.	C++
$a = 2; if ($a = 2) {{}}	$a = 2; if ($a == 2) {{}}	Use ==.	PHP
if ($foo = 9) {{}}	if ($foo -eq 9) {{}}	Use -eq.	PowerShell
System.out.println('data')	System.out.println('data');	Add semicolon.	Java
class = 'info'	class_name = 'info'	'class' is a keyword.	Python
if (b = 28) {}	if (b == 28) {}	Use ==.	Dart
class Person def method end end	class Person def method end end	Correct.	Ruby
SELECT * FROM products WHRE status=72;	SELECT * FROM products WHERE status=72;	Fix WHERE.	SQL
object Order {{ def main(args: Array[String]) = println("result") }}	object Order {{ def main(args: Array[String]): Unit = println("result") }}	Add return type Unit.	Scala
class Product {{ int temp; }};	class Product {{ public: int temp; }};	Make public.	C++
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
[56, 74, 96	[56, 74, 96]	Close bracket.	Ruby
<?php // code ?>	<?php // code ?>	Correct.	PHP
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
function render(result:string){{return result;}} render(85);	function render(result:string){{return result;}} render('result');	Pass correct type.	TypeScript
let mut data=81; let r1=&mut data; let ref2=&mut data;	let mut data=81; {{ let r1=&mut data; }} let ref2=&mut data;	Only one mutable borrow.	Rust
print 'test'	print 'test';	Add semicolon.	Perl
<input type='text' value='result'>	<input type='text' value='result' name='title'>	Add name attribute.	HTML
UPDATE orders SET id='test' WHERE email=41	UPDATE orders SET id='test' WHERE email=41;	Add semicolon.	SQL
int temp = 'info';	String temp = 'info';	Type mismatch.	Dart
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
switch(foo){{ case 30: break; }}	switch(foo){{ case 30: break; default: break; }}	Add default case.	Java
let list=vec![97,95,2]; let head=&list[0]; list.push(44);	let mut list=vec![97,95,2]; let head=list[0]; list.push(44);	Copy instead of reference.	Rust
<user><name>world</name><age>39</age></user	<user><name>world</name><age>39</age></user>	Add closing >.	XML
{{'value':'world'}}	{{"value":"world"}}	Use double quotes.	JSON
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
class Child Entity:	class Child(Entity):	Inheritance uses parentheses.	Python
void render(); int main(){{render();}}	void render(); // prototype int main(){{render();}}	Declare before use.	C++
if (z = 10) {{}}	if (z == 10) {{}}	Use ==.	Kotlin
class Item {{ int item; }} obj.item=5;	class Item {{ public int item; }} obj.item=5;	Make field public.	Java
cin >> x;	int x; cin >> x;	Declare variable.	C++
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(63);	const http = require('http'); http.createServer((req,res) => res.end('test')).listen(63);	Correct.	Node.js
val count = 'result'	val count = "result"	Double quotes.	Kotlin
[x*x for x in arr if x > 68]	[x*x for x in arr if x > 68]	Correct list comprehension.	Python
def foo(): print('value')	def foo(): print('value')	Indent function body.	Python
fn foo() -> i32 {{ 26 }}	fn foo() -> i32 {{ 26 }}	Correct.	Rust
foo	foo()	Add parentheses.	Kotlin
function baz(): void {{ return 89; }}	function baz(): number {{ return 89; }}	Return type mismatch.	TypeScript
let count = 69; count += 1;	let mut count = 69; count += 1;	Need mut to modify.	Rust
while result > 82 result -= 1	while result > 82: result -= 1	Colon missing after while.	Python
if [ $num = 8 ]; then	if [ "$num" = 8 ]; then	Quote variable.	Shell
echo hello hello	echo 'hello hello'	Quote to prevent splitting.	Shell
{{"status":"world" "title":57}}	{{"status":"world", "title":57}}	Add comma.	JSON
'world' + 13	'world' + str(13)	Can't add int to string.	Python
if val = 19 {{}}	if val == 19 {{}}	Use ==.	Swift
<img src='info.jpg'>	<img src='info.jpg' alt='desc'>	Add alt text.	HTML
div {{ color=#333; }}	div {{ color: #333; }}	Use colon.	CSS
y = 29	y=29	No spaces.	Shell
String name = 'world';	String name = 'world';	Correct.	Dart
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
if foo = 93	if foo == 93	Use ==.	Go
raise 'message'	raise Exception('message')	Raise needs an exception class.	Python
disp('hello')	disp('hello')	Correct.	MATLAB
<br></br>	<br>	Self-closing.	HTML
const user:Person = {{name:'result'}};	const user:Person = {{name:'result', age:11}};	Add missing property.	TypeScript
SELECT COUNT(*) FROM orders	SELECT COUNT(*) FROM orders;	Missing semicolon.	SQL
if y > 48 puts 'message'	if y > 48 puts 'message' end	Add 'end'.	Ruby
if result = 1	if result == 1	Use ==.	Ruby
fmt.Println 'message'	fmt.Println('message')	Missing parentheses.	Go
for i=1,23 do print(i) end	for i=1,23 do print(i) end	Correct.	Lua
let count: i32 = "output";	let count: &str = "output";	Type mismatch.	Rust
print 'output'	print('output')	print needs parentheses.	Python
if ($index = 37)	if ($index == 37)	Use ==.	Perl
void main() {{ print('test') }}	void main() {{ print('test'); }}	Add semicolon.	Dart
int[] arr = new int[18]; arr[18] = 5;	int[] arr = new int[18]; if (18 < arr.length) arr[18] = 5;	Check bounds.	Java
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
let val: number = 'value';	let val: string = 'value';	Fix type.	TypeScript
function handle() {{ return {{key:'test'}} }}	function handle() {{ return {{key:'test'}}; }}	Return object on same line.	JavaScript
<hr></hr>	<hr>	Self-closing.	HTML
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
<ul><li>data<li>hello</ul>	<ul><li>data</li><li>hello</li></ul>	Close li.	HTML
if (b = 3) {{}}	if (b === 3) {{}}	Use === for equality.	JavaScript
if b = 21:	if b == 21:	Use == for comparison.	Python
function compute(item) print(item) end	function compute(item) print(item) end	Correct.	Lua
let z: Int = 'hello'	let z: String = 'hello'	Fix type.	Swift
jwt.sign({{id:52}}, 'key');	jwt.sign({{id:52}}, 'key', {{expiresIn:'15m'}});	Add expiration.	Node.js
const data = 19; data = 61;	let data = 19; data = 61;	Cannot reassign const.	JavaScript
print('data')	print('data')	Correct.	R
User.save();	User.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
<user name='info'/>	<user name="info"/>	Double quotes.	XML
int arr[18]; arr[18]=5;	int arr[18]; if(18<18){{}} else arr[18]=5;	Bounds check.	C++
h1 {{ font-size:7px color:blue; }}	h1 {{ font-size:7px; color:blue; }}	Add semicolon.	CSS
print 'hello'	print('hello')	Parentheses for function call.	Lua
arr[88]	if (length(arr) >= 88) arr[88]	Check length.	R
baz	baz()	Add parentheses.	Swift
list[3]	if list.indices.contains(3) {{ list[3] }}	Check index.	Swift
if (result) console.log('yes') else console.log('no')	if (result) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
var x = 77;	var x = 77;	Correct.	Dart
int* user = nullptr; *user=5;	int* user = new int; *user=5;	Allocate memory.	C++
$list[78] = 5;	if (isset($list[78])) $list[78] = 5;	Check existence.	PHP
var x int	var x int	Correct.	Go
JOIN orders ON orders.id = orders.status	JOIN orders ON orders.id = orders.status	Correct.	SQL

if (y = 65) {{}}

if (y === 65) {{}}

Use === for equality.

JavaScript

DELETE FROM orders WHERE status=3

DELETE FROM orders WHERE status=3;

Add semicolon.

SQL

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

if count = 10 then print('data') end

if count == 10 then print('data') end

Use ==.

Lua

for item in range(49) print(item)

for item in range(49): print(item)

Colon after for.

Python

Use style attribute.

CSS

if (index = 17)

if (index == 17)

Use ==.

C++

$a = 2; if ($a = 2) {{}}

$a = 2; if ($a == 2) {{}}

Use ==.

PHP

if ($foo = 9) {{}}

if ($foo -eq 9) {{}}

Use -eq.

PowerShell

System.out.println('data')

System.out.println('data');

Add semicolon.

Java

class = 'info'

class_name = 'info'

'class' is a keyword.

Python

if (b = 28) {}

if (b == 28) {}

Use ==.

Dart

class Person def method end end

Correct.

Ruby

SELECT * FROM products WHRE status=72;

SELECT * FROM products WHERE status=72;

Fix WHERE.

SQL

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

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

Add return type Unit.

Scala

class Product {{ int temp; }};

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

Make public.

C++

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

[56, 74, 96

[56, 74, 96]

Close bracket.

Ruby

<?php // code ?>

Correct.

PHP

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

function render(result:string){{return result;}} render(85);

function render(result:string){{return result;}} render('result');

Pass correct type.

TypeScript

let mut data=81; let r1=&mut data; let ref2=&mut data;

let mut data=81; {{ let r1=&mut data; }} let ref2=&mut data;

Only one mutable borrow.

Rust

print 'test'

print 'test';

Add semicolon.

Perl

Add name attribute.

HTML

UPDATE orders SET id='test' WHERE email=41

UPDATE orders SET id='test' WHERE email=41;

Add semicolon.

SQL

int temp = 'info';

String temp = 'info';

Type mismatch.

Dart

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

Correct.

R

switch(foo){{ case 30: break; }}

switch(foo){{ case 30: break; default: break; }}

Add default case.

Java

let list=vec![97,95,2]; let head=&list[0]; list.push(44);

let mut list=vec![97,95,2]; let head=list[0]; list.push(44);

Copy instead of reference.

Rust

<user><name>world</name><age>39</age></user

<user><name>world</name><age>39</age></user>

Add closing >.

XML

Use double quotes.

JSON

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

class Child Entity:

class Child(Entity):

Inheritance uses parentheses.

Python

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

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

Declare before use.

C++

if (z = 10) {{}}

if (z == 10) {{}}

Use ==.

Kotlin

class Item {{ int item; }} obj.item=5;

class Item {{ public int item; }} obj.item=5;

Make field public.

Java

cin >> x;

int x; cin >> x;

Declare variable.

C++

const http = require('http'); http.createServer((req,res) => res.end('test')).listen(63);

Correct.

Node.js

val count = 'result'

val count = "result"

Double quotes.

Kotlin

[x*x for x in arr if x > 68]

Correct list comprehension.

Python

def foo(): print('value')

Indent function body.

Python

fn foo() -> i32 {{ 26 }}

Correct.

Rust

foo

foo()

Add parentheses.

Kotlin

function baz(): void {{ return 89; }}

function baz(): number {{ return 89; }}

Return type mismatch.

TypeScript

let count = 69; count += 1;

let mut count = 69; count += 1;

Need mut to modify.

Rust

while result > 82 result -= 1

while result > 82: result -= 1

Colon missing after while.

Python

if [ $num = 8 ]; then

if [ "$num" = 8 ]; then

Quote variable.

Shell

echo hello hello

echo 'hello hello'

Quote to prevent splitting.

Shell

Add comma.

JSON

'world' + 13

'world' + str(13)

Can't add int to string.

Python

if val = 19 {{}}

if val == 19 {{}}

Use ==.

Swift

Add alt text.

HTML

div {{ color=#333; }}

div {{ color: #333; }}

Use colon.

CSS

y = 29

y=29

No spaces.

Shell

String name = 'world';

Correct.

Dart

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

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

Type not in union.

TypeScript

if foo = 93

if foo == 93

Use ==.

Go

raise 'message'

raise Exception('message')

Raise needs an exception class.

Python

disp('hello')

Correct.

MATLAB

<br>

Self-closing.

HTML

const user:Person = {{name:'result'}};

const user:Person = {{name:'result', age:11}};

Add missing property.

TypeScript

SELECT COUNT(*) FROM orders

SELECT COUNT(*) FROM orders;

Missing semicolon.

SQL

if y > 48 puts 'message'

if y > 48 puts 'message' end

Add 'end'.

Ruby

if result = 1

if result == 1

Use ==.

Ruby

fmt.Println 'message'

fmt.Println('message')

Missing parentheses.

Go

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

Correct.

Lua

let count: i32 = "output";

let count: &str = "output";

Type mismatch.

Rust

print 'output'

print('output')

print needs parentheses.

Python

if ($index = 37)

if ($index == 37)

Use ==.

Perl

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

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

Add semicolon.

Dart

int[] arr = new int[18]; arr[18] = 5;

int[] arr = new int[18]; if (18 < arr.length) arr[18] = 5;

Check bounds.

Java

lambda x: x+1

Correct lambda.

Python

let val: number = 'value';

let val: string = 'value';

Fix type.

TypeScript

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

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

Return object on same line.

JavaScript

<hr>

Self-closing.

HTML

x = 5; if x > 3, disp('large'), end

Correct.

MATLAB

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

Correct.

PowerShell

<ul><li>data<li>hello</ul>

<ul><li>data</li><li>hello</li></ul>

Close li.

HTML

if (b = 3) {{}}

if (b === 3) {{}}

Use === for equality.

JavaScript

if b = 21:

if b == 21:

Use == for comparison.

Python

function compute(item) print(item) end

Correct.

Lua

let z: Int = 'hello'

let z: String = 'hello'

Fix type.

Swift

jwt.sign({{id:52}}, 'key');

jwt.sign({{id:52}}, 'key', {{expiresIn:'15m'}});

Add expiration.

Node.js

const data = 19; data = 61;

let data = 19; data = 61;

Cannot reassign const.

JavaScript

print('data')

Correct.

R

User.save();

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

Handle promise.

Node.js

ArrayList list = new ArrayList();

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

Use generics.

Java

Double quotes.

XML

int arr[18]; arr[18]=5;

int arr[18]; if(18<18){{}} else arr[18]=5;

Bounds check.

C++

h1 {{ font-size:7px color:blue; }}

h1 {{ font-size:7px; color:blue; }}

Add semicolon.

CSS

print 'hello'

print('hello')

Parentheses for function call.

Lua

arr[88]

if (length(arr) >= 88) arr[88]

Check length.

R

baz

baz()

Add parentheses.

Swift

list[3]

if list.indices.contains(3) {{ list[3] }}

Check index.

Swift

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

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

Missing semicolon.

JavaScript

var x = 77;

Correct.

Dart

int* user = nullptr; *user=5;

int* user = new int; *user=5;

Allocate memory.

C++

$list[78] = 5;

if (isset($list[78])) $list[78] = 5;

Check existence.

PHP

var x int

Correct.

Go

JOIN orders ON orders.id = orders.status

Correct.

SQL