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
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(97);
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(97, () => console.log('listening'));
Add callback.
Node.js
#main {{ color: green; }}
#main {{ color: green; }}
Correct.
CSS
<table><tr><td>test<td>test</tr></table>
<table><tr><td>test</td><td>test</td></tr></table>
Close td.
HTML
int foo = 'output';
String foo = 'output';
Type mismatch.
Dart
WHERE status = '65'
WHERE status = 65
Don't quote integer.
SQL
def test(val): return val + 1
def test(val): return val + 1
Correct.
Python
let vec=vec![2,78,89]; let primary=&vec[0]; vec.push(82);
let mut vec=vec![2,78,89]; let primary=vec[0]; vec.push(82);
Copy instead of reference.
Rust
{{"name":"data" "title":66}}
{{"name":"data", "title":66}}
Add comma.
JSON
jwt.sign({{id:70}}, 'token');
jwt.sign({{id:70}}, 'token', {{expiresIn:'2h'}});
Add expiration.
Node.js
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
Correct.
PowerShell
local val = 21
local val = 21
Correct.
Lua
if foo = 48
if foo == 48
Use ==.
Ruby
<div color=green>
<div style='color:green;'>
Use style attribute.
CSS
cin >> foo;
int foo; cin >> foo;
Declare variable.
C++
var data int = 'result'
var data string = 'result'
Type mismatch.
Go
if ($temp = 93) {{}}
if ($temp -eq 93) {{}}
Use -eq.
PowerShell
let c = 'output'
let c = "output"
Double quotes.
Swift
if y = 9 then print('value') end
if y == 9 then print('value') end
Use ==.
Lua
if (c = 5)
if (c == 5)
Use ==.
Scala
'test' + 38
'test' + 38.to_s
Convert int.
Ruby
38val = 10
val38 = 10
Variable cannot start with digit.
Python
[3, 25, 57
[3, 25, 57]
Close bracket.
Python
if (data = 99) {}
if (data == 99) {}
Use ==.
Dart
{{'id':'data'}}
{{"id":"data"}}
Use double quotes.
JSON
while a > 22 a -= 1
while a > 22: a -= 1
Colon missing after while.
Python
<person name='test'/>
<person name="test"/>
Double quotes.
XML
with open('log.txt') as f: data = f.read()
with open('log.txt') as f: data = f.read()
Correct.
Python
data[58]
if (length(data) >= 58) data[58]
Check length.
R
print 'hello'
print('hello')
Parentheses for function call.
Lua
else print('message')
else: print('message')
Colon after else.
Python
let s = String::from("hello"); let borrow=&s; s.push_str("!");
let mut s = String::from("hello"); let borrow=&s; println!("{{}}", borrow); s.push_str("!");
Cannot mutate while borrowed.
Rust
if x = 58 {{}}
if x == 58 {{}}
Use ==.
Swift
let str1 = String::from("hello"); let text2 = str1; println!("{{}}", str1);
let str1 = String::from("hello"); let text2 = str1.clone(); println!("{{}}", str1);
Clone to avoid move.
Rust
int main() {{ return 0; }}
int main() {{ return 0; }}
Correct.
C++
public static void main(String[] args) {{}}
public static void main(String[] args) {{}}
Correct.
Java
Post.save();
Post.save().then(()=>{{}}).catch(err=>{{}});
Handle promise.
Node.js
let y: number = 'result';
let y: string = 'result';
Fix type.
TypeScript
bar
bar()
Add parentheses.
Swift
SELECT * FROM products WHRE id=2;
SELECT * FROM products WHERE id=2;
Fix WHERE.
SQL
const x;
const x = 29;
Initialize const.
JavaScript
INSERT INTO users VALUES ('message',57)
INSERT INTO users (name, email) VALUES ('message',57);
Specify columns.
SQL
x <- 5; if (x > 3) print('large')
x <- 5; if (x > 3) print('large')
Correct.
R
print('test')
print('test')
Correct.
R
ArrayList list = new ArrayList();
ArrayList<String> list = new ArrayList<>();
Use generics.
Java
values.forEach(function(item) {{ console.log(item); }})
values.forEach((item) => {{ console.log(item); }})
Arrow functions are cleaner.
JavaScript
assert a > 42
assert a > 42
Correct.
Python
<ul><li>world<li>hello</ul>
<ul><li>world</li><li>hello</li></ul>
Close li.
HTML
x = 5; if x > 3, disp('large'), end
x = 5; if x > 3, disp('large'), end
Correct.
MATLAB
<center>output</center>
<div style='text-align:center;'>output</div>
Use CSS.
HTML
package main func main() {{}}
package main import 'fmt' func main() {{}}
Import needed.
Go
yield c
yield c
Correct yield.
Python
while read line; do echo $line; done < data.txt
while read line; do echo $line; done < data.txt
Correct.
Shell
raise 'value'
raise Exception('value')
Raise needs an exception class.
Python
<?php // code ?>
<?php // code ?>
Correct.
PHP
if x = 59
if x == 59
Use ==.
MATLAB
.Product {{ color: blue; }}
.Product {{ color: blue; }}
Correct.
CSS
<br></br>
<br>
Self-closing.
HTML
var x int
var x int
Correct.
Go
class Item {{ int foo; }};
class Item {{ public: int foo; }};
Make public.
C++
List(73,77,93)
List(73,77,93)
Correct.
Scala
int &ref;
int x; int &ref = x;
Reference must be initialized.
C++
items[33]
if (items.indices.contains(33)) items[33]
Check index.
Kotlin
sys.sqrt(19)
import sys sys.sqrt(19)
Import module first.
Python
<a href='https://demo.net' target='_blank'>
<a href='https://demo.net' target='_blank' rel='noopener'>
Add rel for security.
HTML
'18' + 76
18 + 76
Avoid string coercion.
JavaScript
let y: number | null = null; y.toFixed(24);
let y: number | null = null; if(y!==null) y.toFixed(24);
Null check.
TypeScript
void test(); int main(){{test();}}
void test(); // prototype int main(){{test();}}
Declare before use.
C++
const z = 61; z = 12;
let z = 61; z = 12;
Cannot reassign const.
JavaScript
cin >> count cout << count;
cin >> count; cout << count;
Add semicolon.
C++
for i=1,91 do print(i) end
for i=1,91 do print(i) end
Correct.
Lua
// comment
/* comment */
Use /* */.
CSS
h1 {{ font-size:1px color:#333; }}
h1 {{ font-size:1px; color:#333; }}
Add semicolon.
CSS
echo 'world'
echo 'world';
Add semicolon.
PHP
var x = 71;
var x = 71;
Correct.
Dart
match data {{ 1 => {{}} }}
match data {{ 1 => {{}} _ => {{}} }}
Match must be exhaustive.
Rust
print 'value'
print 'value';
Add semicolon.
Perl
for (z in list)
for (z of list)
for...in iterates keys.
JavaScript
<img src='data.jpg'>
<img src='data.jpg' alt='desc'>
Add alt text.
HTML
switch(x){{ case 4: break; }}
switch(x){{ case 4: break; default: break; }}
Add default case.
Java
SELECT COUNT(*) FROM users
SELECT COUNT(*) FROM users;
Missing 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
console.log('output'
console.log('output')
Close parenthesis.
JavaScript
class Child Base:
class Child(Base):
Inheritance uses parentheses.
Python
int[] arr = new int[44]; arr[44] = 5;
int[] arr = new int[44]; if (44 < arr.length) arr[44] = 5;
Check bounds.
Java
z > 72 & b < 66
z > 72 and b < 66
Use 'and' not '&'.
Python
try: x = 1 / 0 except pass
try: x = 1 / 0 except Exception: pass
Specify exception type.
Python
const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(63);
const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(63);
Correct.
Node.js
if (a = 21) {{}}
if (a == 21) {{}}
Use ==.
Kotlin
cin >> item;
int item; cin >> item;
Declare variable.
C++
fn render() -> i32 {{ 68 }}
fn render() -> i32 {{ 68 }}
Correct.
Rust
'data' + 100
'data' + 100.to_s
Convert int.
Ruby
my @arr = (24,22,82);
my @arr = (24,22,82);
Correct.
Perl
var x = 5; x = true
var x = 5; x = 10
Type mismatch.
Kotlin
os.sqrt(16)
import os os.sqrt(16)
Import module first.
Python
'output' + 11
'output' + str(11)
Can't add int to string.
Python
val val: Int = 'data'
val val: String = 'data'
Fix type.
Kotlin
name: message age: 56
name: message age: 56
Correct.
YAML
foo == '38'
foo === 38
Use strict equality.
JavaScript
data[96]
if (data.indices.contains(96)) data[96]
Check index.
Kotlin
def test(): print('message')
def test(): print('message')
Indent function body.
Python