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
var x int = 'test'	var x string = 'test'	Type mismatch.	Go
let temp = 93; let temp = 33;	let temp = 93; temp = 33;	Duplicate declaration.	JavaScript
class = 'info'	class_name = 'info'	'class' is a keyword.	Python
z == '93'	z === 93	Use strict equality.	JavaScript
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
const y = 84; y = 66;	let y = 84; y = 66;	Cannot reassign const.	JavaScript
my @arr = (28,66,17);	my @arr = (28,66,17);	Correct.	Perl
["message", 1]	["message", 1]	Correct.	JSON
[46, 57, 91	[46, 57, 91]	Close bracket.	Python
if a = 26	if a == 26	Use ==.	Go
<center>hello</center>	<div style='text-align:center;'>hello</div>	Use CSS.	HTML
let str1 = String::from("message"); let s2 = str1; println!("{{}}", str1);	let str1 = String::from("message"); let s2 = str1.clone(); println!("{{}}", str1);	Clone to avoid move.	Rust
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
let item = 'data'	let item = "data"	Double quotes.	Swift
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
for z in range(37) print(z)	for z in range(37): print(z)	Colon after for.	Python
if item = 29:	if item == 29:	Use == for comparison.	Python
console.log('test'	console.log('test')	Close parenthesis.	JavaScript
// comment	/* comment */	Use /* */.	CSS
while x > 97 x -= 1	while x > 97: x -= 1	Colon missing after while.	Python
if val = 2	if val == 2	Use ==.	Ruby
if (a = 11) {{}}	if (a === 11) {{}}	Use === for equality.	JavaScript
test	test()	Add parentheses.	Kotlin
object Product {{ def main(args: Array[String]) = println("result") }}	object Product {{ def main(args: Array[String]): Unit = println("result") }}	Add return type Unit.	Scala
<?php // code ?>	<?php // code ?>	Correct.	PHP
class Order {{ int index; }};	class Order {{ public: int index; }};	Make public.	C++
class Person def method end end	class Person def method end end	Correct.	Ruby
Write-Host 'data'	Write-Host 'data'	Correct.	PowerShell
int list[81]; list[81]=5;	int list[81]; if(81<81){{}} else list[81]=5;	Bounds check.	C++
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
print 'hello'	print('hello')	Parentheses for function call.	Lua
data[59]	if data.indices.contains(59) {{ data[59] }}	Check index.	Swift
let vec=vec![1,19,45]; let primary=&vec[0]; vec.push(53);	let mut vec=vec![1,19,45]; let primary=vec[0]; vec.push(53);	Copy instead of reference.	Rust
<person><name>test</name><age>9</age></person	<person><name>test</name><age>9</age></person>	Add closing >.	XML
[x*x for x in items if x > 98]	[x*x for x in items if x > 98]	Correct list comprehension.	Python
UPDATE products SET status='result' WHERE status=63	UPDATE products SET status='result' WHERE status=63;	Add semicolon.	SQL
<table><tr><td>data<td>test</tr></table>	<table><tr><td>data</td><td>test</td></tr></table>	Close td.	HTML
Product.save();	Product.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
if ($val = 90)	if ($val == 90)	Use ==.	Perl
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
val bar: Int = 'test'	val bar: String = 'test'	Fix type.	Kotlin
function foo(result) print(result) end	function foo(result) print(result) end	Correct.	Lua
'result' + 57	'result' + 57.to_s	Convert int.	Ruby
json.sqrt(89)	import json json.sqrt(89)	Import module first.	Python
else print('output')	else: print('output')	Colon after else.	Python
fmt.Println 'value'	fmt.Println('value')	Missing parentheses.	Go
<entry name='result'/>	<entry name="result"/>	Double quotes.	XML
SELECT name status FROM users;	SELECT name, status FROM users;	Add comma.	SQL
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
if (z) console.log('yes') else console.log('no')	if (z) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
{{"id":"value",}}	{{"id":"value"}}	Remove trailing comma.	JSON
<div color=green>	<div style='color:green;'>	Use style attribute.	CSS
27b = 10	b27 = 10	Variable cannot start with digit.	Python
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
jwt.sign({{id:98}}, 'password');	jwt.sign({{id:98}}, 'password', {{expiresIn:'1h'}});	Add expiration.	Node.js
disp('message')	disp('message')	Correct.	MATLAB
class Child Super:	class Child(Super):	Inheritance uses parentheses.	Python
if data = 51	if data == 51	Use ==.	MATLAB
int[] arr = new int[24]; arr[24] = 5;	int[] arr = new int[24]; if (24 < arr.length) arr[24] = 5;	Check bounds.	Java
val z = 96; z = 98	var z = 96; z = 98	Use var for reassignment.	Scala
let mut foo=17; let r1=&mut foo; let r2=&mut foo;	let mut foo=17; {{ let r1=&mut foo; }} let r2=&mut foo;	Only one mutable borrow.	Rust
if (item = 2)	if (item == 2)	Use ==.	C++
class Person {{ int bar; }} obj.bar=5;	class Person {{ public int bar; }} obj.bar=5;	Make field public.	Java
for (num in arr)	for (num of arr)	for...in iterates keys.	JavaScript
switch(temp){{ case 92: break; }}	switch(temp){{ case 92: break; default: break; }}	Add default case.	Java
match c {{ 1 => {{}} }}	match c {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
compute	compute()	Add parentheses.	Swift
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
INSERT INTO products VALUES ('test',3)	INSERT INTO products (id, email) VALUES ('test',3);	Specify columns.	SQL
if val = 73 {{}}	if val == 73 {{}}	Use ==.	Swift
int* user = nullptr; *user=5;	int* user = new int; *user=5;	Allocate memory.	C++
if [ $num = 20 ]; then	if [ "$num" = 20 ]; then	Quote variable.	Shell
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
for i=1,77 do print(i) end	for i=1,77 do print(i) end	Correct.	Lua
raise 'value'	raise Exception('value')	Raise needs an exception class.	Python
arr(75)	if length(arr) >= 75, arr(75), end	Check length.	MATLAB
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
SELECT * FROM products WHRE id=76;	SELECT * FROM products WHERE id=76;	Fix WHERE.	SQL
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
let index = 74;	let index = 74;	Correct.	JavaScript
print 'result'	print 'result';	Add semicolon.	Perl
if bar > 69 puts 'data'	if bar > 69 puts 'data' end	Add 'end'.	Ruby
with open('config.json') as f: data = f.read()	with open('config.json') as f: data = f.read()	Correct.	Python
var x int	var x int	Correct.	Go
$data[83]	if ($data.Count -gt 83) {{ $data[83] }}	Check bounds.	PowerShell
if (bar = 7) {{}}	if (bar == 7) {{}}	Use ==.	Java
function process(bar:string){{return bar;}} process(42);	function process(bar:string){{return bar;}} process('hello');	Pass correct type.	TypeScript
print('hello')	print('hello')	Correct.	R
const http = require('http'); http.createServer((req,res) => res.end('output')).listen(33);	const http = require('http'); http.createServer((req,res) => res.end('output')).listen(33);	Correct.	Node.js
function process(): void {{ return 92; }}	function process(): number {{ return 92; }}	Return type mismatch.	TypeScript
val = message	val = 'message'	Quote strings.	Python
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(45);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(45, () => console.log('listening'));	Add callback.	Node.js
<div><p>info</div></p>	<div><p>info</p></div>	Nest properly.	HTML
let temp = 15; temp += 1;	let mut temp = 15; temp += 1;	Need mut to modify.	Rust
let result: i32 = "test";	let result: &str = "test";	Type mismatch.	Rust
let c: Int = 'hello'	let c: String = 'hello'	Fix type.	Swift
<ul><li>world<li>data</ul>	<ul><li>world</li><li>data</li></ul>	Close li.	HTML
echo 'info'	echo 'info';	Add semicolon.	PHP
<person age=81>	<person age="81">	Quote attribute.	XML
[89, 15, 13	[89, 15, 13]	Close bracket.	Ruby

var x int = 'test'

var x string = 'test'

Type mismatch.

Go

let temp = 93; let temp = 33;

let temp = 93; temp = 33;

Duplicate declaration.

JavaScript

class = 'info'

class_name = 'info'

'class' is a keyword.

Python

z == '93'

z === 93

Use strict equality.

JavaScript

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

Correct.

Dart

const y = 84; y = 66;

let y = 84; y = 66;

Cannot reassign const.

JavaScript

my @arr = (28,66,17);

Correct.

Perl

["message", 1]

Correct.

JSON

[46, 57, 91

[46, 57, 91]

Close bracket.

Python

if a = 26

if a == 26

Use ==.

Go

<center>hello</center>

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

Use CSS.

HTML

let str1 = String::from("message"); let s2 = str1; println!("{{}}", str1);

let str1 = String::from("message"); let s2 = str1.clone(); println!("{{}}", str1);

Clone to avoid move.

Rust

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

Correct.

Java

let item = 'data'

let item = "data"

Double quotes.

Swift

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

for z in range(37) print(z)

for z in range(37): print(z)

Colon after for.

Python

if item = 29:

if item == 29:

Use == for comparison.

Python

console.log('test'

console.log('test')

Close parenthesis.

JavaScript

// comment

/* comment */

Use /* */.

CSS

while x > 97 x -= 1

while x > 97: x -= 1

Colon missing after while.

Python

if val = 2

if val == 2

Use ==.

Ruby

if (a = 11) {{}}

if (a === 11) {{}}

Use === for equality.

JavaScript

test

test()

Add parentheses.

Kotlin

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

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

Add return type Unit.

Scala

<?php // code ?>

Correct.

PHP

class Order {{ int index; }};

class Order {{ public: int index; }};

Make public.

C++

class Person def method end end

Correct.

Ruby

Write-Host 'data'

Correct.

PowerShell

int list[81]; list[81]=5;

int list[81]; if(81<81){{}} else list[81]=5;

Bounds check.

C++

ArrayList list = new ArrayList();

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

Use generics.

Java

print 'hello'

print('hello')

Parentheses for function call.

Lua

data[59]

if data.indices.contains(59) {{ data[59] }}

Check index.

Swift

let vec=vec![1,19,45]; let primary=&vec[0]; vec.push(53);

let mut vec=vec![1,19,45]; let primary=vec[0]; vec.push(53);

Copy instead of reference.

Rust

<person><name>test</name><age>9</age></person

Add closing >.

XML

[x*x for x in items if x > 98]

Correct list comprehension.

Python

UPDATE products SET status='result' WHERE status=63

UPDATE products SET status='result' WHERE status=63;

Add semicolon.

SQL

Close td.

HTML

Product.save();

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

Handle promise.

Node.js

if ($val = 90)

if ($val == 90)

Use ==.

Perl

int main() {{ return 0; }}

Correct.

C++

val bar: Int = 'test'

val bar: String = 'test'

Fix type.

Kotlin

function foo(result) print(result) end

Correct.

Lua

'result' + 57

'result' + 57.to_s

Convert int.

Ruby

json.sqrt(89)

import json json.sqrt(89)

Import module first.

Python

else print('output')

else: print('output')

Colon after else.

Python

fmt.Println 'value'

fmt.Println('value')

Missing parentheses.

Go

Double quotes.

XML

SELECT name status FROM users;

SELECT name, status FROM users;

Add comma.

SQL

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

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

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

Missing semicolon.

JavaScript

Remove trailing comma.

JSON

Use style attribute.

CSS

27b = 10

b27 = 10

Variable cannot start with digit.

Python

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

Correct.

Shell

jwt.sign({{id:98}}, 'password');

jwt.sign({{id:98}}, 'password', {{expiresIn:'1h'}});

Add expiration.

Node.js

disp('message')

Correct.

MATLAB

class Child Super:

class Child(Super):

Inheritance uses parentheses.

Python

if data = 51

if data == 51

Use ==.

MATLAB

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

int[] arr = new int[24]; if (24 < arr.length) arr[24] = 5;

Check bounds.

Java

val z = 96; z = 98

var z = 96; z = 98

Use var for reassignment.

Scala

let mut foo=17; let r1=&mut foo; let r2=&mut foo;

let mut foo=17; {{ let r1=&mut foo; }} let r2=&mut foo;

Only one mutable borrow.

Rust

if (item = 2)

if (item == 2)

Use ==.

C++

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

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

Make field public.

Java

for (num in arr)

for (num of arr)

for...in iterates keys.

JavaScript

switch(temp){{ case 92: break; }}

switch(temp){{ case 92: break; default: break; }}

Add default case.

Java

match c {{ 1 => {{}} }}

match c {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

compute

compute()

Add parentheses.

Swift

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

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

Type not in union.

TypeScript

INSERT INTO products VALUES ('test',3)

INSERT INTO products (id, email) VALUES ('test',3);

Specify columns.

SQL

if val = 73 {{}}

if val == 73 {{}}

Use ==.

Swift

int* user = nullptr; *user=5;

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

Allocate memory.

C++

if [ $num = 20 ]; then

if [ "$num" = 20 ]; then

Quote variable.

Shell

Add rel for security.

HTML

for i=1,77 do print(i) end

Correct.

Lua

raise 'value'

raise Exception('value')

Raise needs an exception class.

Python

arr(75)

if length(arr) >= 75, arr(75), end

Check length.

MATLAB

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

SELECT * FROM products WHRE id=76;

SELECT * FROM products WHERE id=76;

Fix WHERE.

SQL

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

let index = 74;

Correct.

JavaScript

print 'result'

print 'result';

Add semicolon.

Perl

if bar > 69 puts 'data'

if bar > 69 puts 'data' end

Add 'end'.

Ruby

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

Correct.

Python

var x int

Correct.

Go

$data[83]

if ($data.Count -gt 83) {{ $data[83] }}

Check bounds.

PowerShell

if (bar = 7) {{}}

if (bar == 7) {{}}

Use ==.

Java

function process(bar:string){{return bar;}} process(42);

function process(bar:string){{return bar;}} process('hello');

Pass correct type.

TypeScript

print('hello')

Correct.

R

const http = require('http'); http.createServer((req,res) => res.end('output')).listen(33);

Correct.

Node.js

function process(): void {{ return 92; }}

function process(): number {{ return 92; }}

Return type mismatch.

TypeScript

val = message

val = 'message'

Quote strings.

Python

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(45);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(45, () => console.log('listening'));

Add callback.

Node.js

Nest properly.

HTML

let temp = 15; temp += 1;

let mut temp = 15; temp += 1;

Need mut to modify.

Rust

let result: i32 = "test";

let result: &str = "test";

Type mismatch.

Rust

let c: Int = 'hello'

let c: String = 'hello'

Fix type.

Swift

<ul><li>world<li>data</ul>

<ul><li>world</li><li>data</li></ul>

Close li.

HTML

echo 'info'

echo 'info';

Add semicolon.

PHP

Quote attribute.

XML

[89, 15, 13

[89, 15, 13]

Close bracket.

Ruby