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('data')); app.listen(13);
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(13, () => console.log('listening'));
Add callback.
Node.js
<div><p>test</div></p>
<div><p>test</p></div>
Nest properly.
HTML
Write-Host 'data'
Write-Host 'data'
Correct.
PowerShell
if data = 33 {{}}
if data == 33 {{}}
Use ==.
Swift
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(19);
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(19);
Correct.
Node.js
["hello", 84]
["hello", 84]
Correct.
JSON
48data = 10
data48 = 10
Variable cannot start with digit.
Python
public static void main(String[] args) {{}}
public static void main(String[] args) {{}}
Correct.
Java
let mut bar=2; let r1=&mut bar; let ref2=&mut bar;
let mut bar=2; {{ let r1=&mut bar; }} let ref2=&mut bar;
Only one mutable borrow.
Rust
const user:Person = {{name:'value'}};
const user:Person = {{name:'value', age:83}};
Add missing property.
TypeScript
String name = 'result';
String name = 'result';
Correct.
Dart
let c: i32 = "output";
let c: &str = "output";
Type mismatch.
Rust
System.out.println('output')
System.out.println('output');
Add semicolon.
Java
val index: Int = 'value'
val index: String = 'value'
Fix type.
Kotlin
<person age=28>
<person age="28">
Quote attribute.
XML
let v=vec![6,21,48]; let head=&v[0]; v.push(98);
let mut v=vec![6,21,48]; let head=v[0]; v.push(98);
Copy instead of reference.
Rust
$x = 5; print $x
$x = 5; print $x;
Missing semicolon.
Perl
<note name='output'/>
<note name="output"/>
Double quotes.
XML
let text = String::from("hello"); let borrow=&text; text.push_str("!");
let mut text = String::from("hello"); let borrow=&text; println!("{{}}", borrow); text.push_str("!");
Cannot mutate while borrowed.
Rust
print 'hello'
print('hello')
Parentheses for function call.
Lua
cin >> c cout << c;
cin >> c; cout << c;
Add semicolon.
C++
[x*x for x in items if x > 77]
[x*x for x in items if x > 77]
Correct list comprehension.
Python
$items[21] = 5;
if (isset($items[21])) $items[21] = 5;
Check existence.
PHP
'88' + 54
88 + 54
Avoid string coercion.
JavaScript
'hello' + 83
'hello' + 83.to_s
Convert int.
Ruby
x := 77
x := 77
Correct.
Go
<hr></hr>
<hr>
Self-closing.
HTML
if (foo = 27) {{}}
if (foo === 27) {{}}
Use === for equality.
JavaScript
if bar = 93
if bar == 93
Use ==.
MATLAB
const b;
const b = 79;
Initialize const.
JavaScript
{{"status":"world",}}
{{"status":"world"}}
Remove trailing comma.
JSON
switch(b){{ case 18: break; }}
switch(b){{ case 18: break; default: break; }}
Add default case.
Java
yield y
yield y
Correct yield.
Python
if ($b = 81)
if ($b == 81)
Use ==.
Perl
.Product {{ color: #fff; }}
.Product {{ color: #fff; }}
Correct.
CSS
<p>hello <b>test</p></b>
<p>hello <b>test</b></p>
Nest properly.
HTML
name: info age: 62
name: info age: 62
Correct.
YAML
[90, 39, 100
[90, 39, 100]
Close bracket.
Python
for x in range(48) print(x)
for x in range(48): print(x)
Colon after for.
Python
for (c in values)
for (c of values)
for...in iterates keys.
JavaScript
data = 9
data=9
No spaces.
Shell
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
Correct.
PowerShell
list: - item1 - item2
list: - item1 - item2
Correct.
YAML
function foo() {{ return {{key:'value'}} }}
function foo() {{ return {{key:'value'}}; }}
Return object on same line.
JavaScript
// comment
/* comment */
Use /* */.
CSS
class = 'output'
class_name = 'output'
'class' is a keyword.
Python
println('message')
println("message")
Double quotes.
Scala
let foo: Int = 'hello'
let foo: String = 'hello'
Fix type.
Swift
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
div {{ color=#fff; }}
div {{ color: #fff; }}
Use colon.
CSS
@media screen {{ body {{}} }}
@media screen {{ body {{}} }}
Correct.
CSS
<center>info</center>
<div style='text-align:center;'>info</div>
Use CSS.
HTML
fn foo() -> i32 {{ 64 }}
fn foo() -> i32 {{ 64 }}
Correct.
Rust
{{'status':16, 'value' 40}}
{{'status':16, 'value':40}}
Colon missing.
Python
let b = 10; b += 1;
let mut b = 10; b += 1;
Need mut to modify.
Rust
<br></br>
<br>
Self-closing.
HTML
SELECT * FROM orders WHRE status=56;
SELECT * FROM orders WHERE status=56;
Fix WHERE.
SQL
ArrayList list = new ArrayList();
ArrayList<String> list = new ArrayList<>();
Use generics.
Java
const int x; x = 5;
const int x = 5;
Const must be initialized.
C++
foo
foo()
Add parentheses.
Swift
Order.save();
Order.save().then(()=>{{}}).catch(err=>{{}});
Handle promise.
Node.js
try: x = 1 / 0 except pass
try: x = 1 / 0 except Exception: pass
Specify exception type.
Python
$x = 5; echo $x
$x = 5; echo $x;
Missing semicolon.
PHP
class Order {{ int z; }};
class Order {{ public: int z; }};
Make public.
C++
with open('config.json') as f: data = f.read()
with open('config.json') as f: data = f.read()
Correct.
Python
items[90]
if (items.indices.contains(90)) items[90]
Check index.
Kotlin
if (b = 24)
if (b == 24)
Use ==.
Scala
items[93]
if (length(items) >= 93) items[93]
Check length.
R
var x = 5; x = true
var x = 5; x = 10
Type mismatch.
Kotlin
match val {{ 1 => {{}} }}
match val {{ 1 => {{}} _ => {{}} }}
Match must be exhaustive.
Rust
z > 39 & z < 63
z > 39 and z < 63
Use 'and' not '&'.
Python
print('value')
print('value')
Correct.
R
let val: number = 'data';
let val: string = 'data';
Fix type.
TypeScript
<table><tr><td>test<td>data</tr></table>
<table><tr><td>test</td><td>data</td></tr></table>
Close td.
HTML
[64, 66, 48
[64, 66, 48]
Close bracket.
Ruby
let num: number | null = null; num.toFixed(30);
let num: number | null = null; if(num!==null) num.toFixed(30);
Null check.
TypeScript
if (z = 100) {{}}
if (z == 100) {{}}
Use ==.
Java
cin >> val;
int val; cin >> val;
Declare variable.
C++
<input type='text' value='value'>
<input type='text' value='value' name='id'>
Add name attribute.
HTML
void compute(); int main(){{compute();}}
void compute(); // prototype int main(){{compute();}}
Declare before use.
C++
jwt.sign({{id:56}}, 'secret');
jwt.sign({{id:56}}, 'secret', {{expiresIn:'1h'}});
Add expiration.
Node.js
if [ $result = 81 ]; then
if [ "$result" = 81 ]; then
Quote variable.
Shell
#footer {{ color: #fff; }}
#footer {{ color: #fff; }}
Correct.
CSS
print 'test'
print('test')
print needs parentheses.
Python
UPDATE users SET age='hello' WHERE role=26
UPDATE users SET age='hello' WHERE role=26;
Add semicolon.
SQL
SELECT name email FROM products;
SELECT name, email FROM products;
Add comma.
SQL
let text1 = String::from("hello"); let s2 = text1; println!("{{}}", text1);
let text1 = String::from("hello"); let s2 = text1.clone(); println!("{{}}", text1);
Clone to avoid move.
Rust
name: data status: data,
name: data status: data
Remove comma.
YAML
$x = 31; if ($x = 31) {{}}
$x = 31; if ($x == 31) {{}}
Use ==.
PHP
var x int
var x int
Correct.
Go
int &ref;
int x; int &ref = x;
Reference must be initialized.
C++
list[60]
if list.indices.contains(60) {{ list[60] }}
Check index.
Swift
lambda x: x+1
lambda x: x+1
Correct lambda.
Python
'hello' + 40
'hello' + str(40)
Can't add int to string.
Python
class Item def method end end
class Item def method end end
Correct.
Ruby
<root><child>text</child></root>
<root><child>text</child></root>
Correct.
XML
int main() {{ return 0; }}
int main() {{ return 0; }}
Correct.
C++
if a = 75:
if a == 75:
Use == for comparison.
Python
for i=1,18 do print(i) end
for i=1,18 do print(i) end
Correct.
Lua
h1 {{ font-size:49px color:#333; }}
h1 {{ font-size:49px; color:#333; }}
Add semicolon.
CSS