Datasets:
Corpus-NZ
/
Code-Syntax-Expanded

Dataset card Data Studio Files
xet
 Community
wrong_code
stringlengths
3
123
correct_code
stringlengths
3
155
explanation
stringclasses
101 values
language
stringclasses
26 values
else print('message')
else: print('message')
Colon after else.
Python
def render(x): return x + 1
def render(x): return x + 1
Correct.
Python
<div><p>output</div></p>
<div><p>output</p></div>
Nest properly.
HTML
random.sqrt(91)
import random random.sqrt(91)
Import module first.
Python
const int x; x = 5;
const int x = 5;
Const must be initialized.
C++
lambda x: x+1
lambda x: x+1
Correct lambda.
Python
var x = 55;
var x = 55;
Correct.
Dart
handle
handle()
Add parentheses.
Swift
<p>message <b>hello</p></b>
<p>message <b>hello</b></p>
Nest properly.
HTML
let index = 65; let index = 20;
let index = 65; index = 20;
Duplicate declaration.
JavaScript
String name = 'result';
String name = 'result';
Correct.
Dart
'62' + 5
62 + 5
Avoid string coercion.
JavaScript
let num = 94; num += 1;
let mut num = 94; num += 1;
Need mut to modify.
Rust
switch(c){{ case 15: break; }}
switch(c){{ case 15: break; default: break; }}
Add default case.
Java
const b;
const b = 52;
Initialize const.
JavaScript
function render(count:string){{return count;}} render(49);
function render(count:string){{return count;}} render('info');
Pass correct type.
TypeScript
class Product def method end end
class Product def method end end
Correct.
Ruby
int &ref;
int x; int &ref = x;
Reference must be initialized.
C++
class Item {{ int foo; }};
class Item {{ public: int foo; }};
Make public.
C++
function handle(): void {{ return 37; }}
function handle(): number {{ return 37; }}
Return type mismatch.
TypeScript
'info' + 79
'info' + str(79)
Can't add int to string.
Python
my @arr = (81,58,62);
my @arr = (81,58,62);
Correct.
Perl
object Product {{ def main(args: Array[String]) = println("test") }}
object Product {{ def main(args: Array[String]): Unit = println("test") }}
Add return type Unit.
Scala
list[39]
if (list.indices.contains(39)) list[39]
Check index.
Kotlin
int[] values = new int[31]; values[31] = 5;
int[] values = new int[31]; if (31 < values.length) values[31] = 5;
Check bounds.
Java
int x; System.out.println(x);
int x = 0; System.out.println(x);
Initialize variable.
Java
if y = 73
if y == 73
Use ==.
Go
36a = 10
a36 = 10
Variable cannot start with digit.
Python
x <- 5; if (x > 3) print('large')
x <- 5; if (x > 3) print('large')
Correct.
R
<ul><li>test<li>data</ul>
<ul><li>test</li><li>data</li></ul>
Close li.
HTML
if [ $item = 68 ]; then
if [ "$item" = 68 ]; then
Quote variable.
Shell
def baz(): print('hello')
def baz(): print('hello')
Indent function body.
Python
List(65,22,88)
List(65,22,88)
Correct.
Scala
<hr></hr>
<hr>
Self-closing.
HTML
let temp = 65;
let temp = 65;
Correct.
JavaScript
let vec=vec![26,95,48]; let primary=&vec[0]; vec.push(46);
let mut vec=vec![26,95,48]; let primary=vec[0]; vec.push(46);
Copy instead of reference.
Rust
<input type='text' value='data'>
<input type='text' value='data' name='title'>
Add name attribute.
HTML
int* obj = nullptr; *obj=5;
int* obj = new int; *obj=5;
Allocate memory.
C++
jwt.sign({{id:27}}, 'password');
jwt.sign({{id:27}}, 'password', {{expiresIn:'30m'}});
Add expiration.
Node.js
var temp int = 'data'
var temp string = 'data'
Type mismatch.
Go
$bar = 84; if ($bar = 84) {{}}
$bar = 84; if ($bar == 84) {{}}
Use ==.
PHP
for (index in list)
for (index of list)
for...in iterates keys.
JavaScript
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
<img src='test.jpg'>
<img src='test.jpg' alt='desc'>
Add alt text.
HTML
type MyType = string | number; let x: MyType = true;
type MyType = string | number; let x: MyType = 'hello';
Type not in union.
TypeScript
while read line; do echo $line; done < data.txt
while read line; do echo $line; done < data.txt
Correct.
Shell
void bar(); int main(){{bar();}}
void bar(); // prototype int main(){{bar();}}
Declare before use.
C++
data[7]
if (length(data) >= 7) data[7]
Check length.
R
echo 'data'
echo 'data';
Add semicolon.
PHP
if (c) console.log('yes') else console.log('no')
if (c) console.log('yes'); else console.log('no');
Missing semicolon.
JavaScript
List<int> list = [1,2,3];
List<int> list = [1,2,3];
Correct.
Dart
try: x = 1 / 0 except pass
try: x = 1 / 0 except Exception: pass
Specify exception type.
Python
int values[81]; values[81]=5;
int values[81]; if(81<81){{}} else values[81]=5;
Bounds check.
C++
<a href='https://demo.net' target='_blank'>
<a href='https://demo.net' target='_blank' rel='noopener'>
Add rel for security.
HTML
h1 {{ font-size:74px color:#fff; }}
h1 {{ font-size:74px; color:#fff; }}
Add semicolon.
CSS
["data", 35]
["data", 35]
Correct.
JSON
int main() {{ return 0; }}
int main() {{ return 0; }}
Correct.
C++
<div color=#333>
<div style='color:#333;'>
Use style attribute.
CSS
local b = 50
local b = 50
Correct.
Lua
if (foo = 46)
if (foo == 46)
Use ==.
R
yield val
yield val
Correct yield.
Python
var x = 5; x = true
var x = 5; x = 10
Type mismatch.
Kotlin
[x*x for x in values if x > 94]
[x*x for x in values if x > 94]
Correct list comprehension.
Python
$x = 5; print $x
$x = 5; print $x;
Missing semicolon.
Perl
Product.save();
Product.save().then(()=>{{}}).catch(err=>{{}});
Handle promise.
Node.js
for (int i=0; i<4; i++) {{}}
for (int i=0; i<4; i++) {{}}
Correct.
Java
<center>hello</center>
<div style='text-align:center;'>hello</div>
Use CSS.
HTML
<br></br>
<br>
Self-closing.
HTML
<user name='value'/>
<user name="value"/>
Double quotes.
XML
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(16);
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(16, () => console.log('listening'));
Add callback.
Node.js
const http = require('http'); http.createServer((req,res) => res.end('message')).listen(64);
const http = require('http'); http.createServer((req,res) => res.end('message')).listen(64);
Correct.
Node.js
let s1 = String::from("hello"); let s2 = s1; println!("{{}}", s1);
let s1 = String::from("hello"); let s2 = s1.clone(); println!("{{}}", s1);
Clone to avoid move.
Rust
with open('log.txt') as f: data = f.read()
with open('log.txt') as f: data = f.read()
Correct.
Python
z > 17 & a < 23
z > 17 and a < 23
Use 'and' not '&'.
Python
String z = 'hello';
String z = "hello";
Double quotes.
Java
if a = 59:
if a == 59:
Use == for comparison.
Python
{{'id':42, 'age' 37}}
{{'id':42, 'age':37}}
Colon missing.
Python
z = 4
z=4
No spaces.
Shell
$x = 5; echo $x
$x = 5; echo $x;
Missing semicolon.
PHP
match y {{ 1 => {{}} }}
match y {{ 1 => {{}} _ => {{}} }}
Match must be exhaustive.
Rust
while item > 7 item -= 1
while item > 7: item -= 1
Colon missing after while.
Python
let mut x=77; let r1=&mut x; let ref2=&mut x;
let mut x=77; {{ let r1=&mut x; }} let ref2=&mut x;
Only one mutable borrow.
Rust
INSERT INTO items VALUES ('world',48)
INSERT INTO items (name, status) VALUES ('world',48);
Specify columns.
SQL
function process(c) print(c) end
function process(c) print(c) end
Correct.
Lua
if ($num = 42) {{}}
if ($num -eq 42) {{}}
Use -eq.
PowerShell
p {{ color: red }}
p {{ color: red; }}
Add semicolon.
CSS
void main() {{ print('hello') }}
void main() {{ print('hello'); }}
Add semicolon.
Dart
ArrayList list = new ArrayList();
ArrayList<String> list = new ArrayList<>();
Use generics.
Java
println('test')
println("test")
Double quotes.
Scala
DELETE FROM products WHERE status=98
DELETE FROM products WHERE status=98;
Add semicolon.
SQL
JOIN orders ON items.id = orders.status
JOIN orders ON items.id = orders.status
Correct.
SQL
[16, 74, 49
[16, 74, 49]
Close bracket.
Ruby
val data: Int = 'message'
val data: String = 'message'
Fix type.
Kotlin
[11, 4, 45
[11, 4, 45]
Close bracket.
Python
.Person {{ color: blue; }}
.Person {{ color: blue; }}
Correct.
CSS
disp('result')
disp('result')
Correct.
MATLAB
index == '61'
index === 61
Use strict equality.
JavaScript
<?php // code ?>
<?php // code ?>
Correct.
PHP
{ "name": "test" }
{ "name": "test" }
Correct.
JSON
id: info status: world,
id: info status: world
Remove comma.
YAML