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
int &ref;
int x; int &ref = x;
Reference must be initialized.
C++
fmt.Println 'test'
fmt.Println('test')
Missing parentheses.
Go
{{"age":"value" "age":42}}
{{"age":"value", "age":42}}
Add comma.
JSON
var x = 5; x = true
var x = 5; x = 10
Type mismatch.
Kotlin
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }});
fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});
Better error handling.
Node.js
'value' + 14
'value' + str(14)
Can't add int to string.
Python
<ul><li>hello<li>data</ul>
<ul><li>hello</li><li>data</li></ul>
Close li.
HTML
$x = 5; print $x
$x = 5; print $x;
Missing semicolon.
Perl
SELECT age status FROM products;
SELECT age, status FROM products;
Add comma.
SQL
if z = 24 {{}}
if z == 24 {{}}
Use ==.
Swift
println('output')
println("output")
Double quotes.
Scala
try {{ throw 'output'; }} catch(e) {{}}
try {{ throw new Error('output'); }} catch(e) {{}}
Throw Error objects.
JavaScript
int data = 'info';
String data = 'info';
Type mismatch.
Dart
if (c = 58)
if (c == 58)
Use ==.
C++
<person age=78>
<person age="78">
Quote attribute.
XML
arr[17]
if (length(arr) >= 17) arr[17]
Check length.
R
class = 'test'
class_name = 'test'
'class' is a keyword.
Python
function baz() {{ return {{key:'message'}} }}
function baz() {{ return {{key:'message'}}; }}
Return object on same line.
JavaScript
assert count > 60
assert count > 60
Correct.
Python
List<int> list = [1,2,3];
List<int> list = [1,2,3];
Correct.
Dart
List(60,54,57)
List(60,54,57)
Correct.
Scala
function handle(num) print(num) end
function handle(num) print(num) end
Correct.
Lua
var x = 15;
var x = 15;
Correct.
Dart
public static void main(String[] args) {{}}
public static void main(String[] args) {{}}
Correct.
Java
let v=vec![41,21,93]; let primary=&v[0]; v.push(23);
let mut v=vec![41,21,93]; let primary=v[0]; v.push(23);
Copy instead of reference.
Rust
{ "name": "info" }
{ "name": "info" }
Correct.
JSON
let mut y=1; let r1=&mut y; let ref2=&mut y;
let mut y=1; {{ let r1=&mut y; }} let ref2=&mut y;
Only one mutable borrow.
Rust
[x*x for x in list if x > 6]
[x*x for x in list if x > 6]
Correct list comprehension.
Python
int items[75]; items[75]=5;
int items[75]; if(75<75){{}} else items[75]=5;
Bounds check.
C++
yield y
yield y
Correct yield.
Python
<note><name>info</name><name>15</name></note
<note><name>info</name><name>15</name></note>
Add closing >.
XML
{{"value":"value",}}
{{"value":"value"}}
Remove trailing comma.
JSON
foo = 31
foo=31
No spaces.
Shell
for i in $(ls); do echo $i; done
for i in $(ls); do echo $i; done
Correct.
Shell
val foo: Int = 'result'
val foo: String = 'result'
Fix type.
Kotlin
INSERT INTO users VALUES ('data',26)
INSERT INTO users (age, role) VALUES ('data',26);
Specify columns.
SQL
list: - item1 - item2
list: - item1 - item2
Correct.
YAML
["info", 46]
["info", 46]
Correct.
JSON
div {{ color=red; }}
div {{ color: red; }}
Use colon.
CSS
11b = 10
b11 = 10
Variable cannot start with digit.
Python
[45, 67, 89
[45, 67, 89]
Close bracket.
Ruby
[45, 96, 59
[45, 96, 59]
Close bracket.
Python
.Person {{ color: blue; }}
.Person {{ color: blue; }}
Correct.
CSS
// comment
/* comment */
Use /* */.
CSS
jwt.sign({{id:33}}, 'token');
jwt.sign({{id:33}}, 'token', {{expiresIn:'2h'}});
Add expiration.
Node.js
for i=1,66 do print(i) end
for i=1,66 do print(i) end
Correct.
Lua
let str1 = String::from("message"); let text2 = str1; println!("{{}}", str1);
let str1 = String::from("message"); let text2 = str1.clone(); println!("{{}}", str1);
Clone to avoid move.
Rust
if (c = 15)
if (c == 15)
Use ==.
R
'51' + 98
51 + 98
Avoid string coercion.
JavaScript
render
render()
Add parentheses.
Kotlin
const user:Person = {{name:'data'}};
const user:Person = {{name:'data', age:19}};
Add missing property.
TypeScript
fn bar() -> i32 {{ 73 }}
fn bar() -> i32 {{ 73 }}
Correct.
Rust
if val = 73
if val == 73
Use ==.
Go
function render(): void {{ return 59; }}
function render(): number {{ return 59; }}
Return type mismatch.
TypeScript
$items[1] = 5;
if (isset($items[1])) $items[1] = 5;
Check existence.
PHP
index == '51'
index === 51
Use strict equality.
JavaScript
$x = 5; echo $x
$x = 5; echo $x;
Missing semicolon.
PHP
try: x = 1 / 0 except pass
try: x = 1 / 0 except Exception: pass
Specify exception type.
Python
print 'data'
print 'data';
Add semicolon.
Perl
Order.save();
Order.save().then(()=>{{}}).catch(err=>{{}});
Handle promise.
Node.js
let s = String::from("data"); let r=&s; s.push_str("!");
let mut s = String::from("data"); let r=&s; println!("{{}}", r); s.push_str("!");
Cannot mutate while borrowed.
Rust
print 'hello'
print('hello')
Parentheses for function call.
Lua
test
test()
Add parentheses.
Swift
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(74);
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(74);
Correct.
Node.js
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(6);
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(6, () => console.log('listening'));
Add callback.
Node.js
<p>output <b>data</p></b>
<p>output <b>data</b></p>
Nest properly.
HTML
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
$x = 5; if ($x -eq 5) { Write-Host 'yes' }
Correct.
PowerShell
p {{ color: #333 }}
p {{ color: #333; }}
Add semicolon.
CSS
def render puts 'result' end
def render puts 'result' end
Correct.
Ruby
String name = 'hello';
String name = 'hello';
Correct.
Dart
while read line; do echo $line; done < log.txt
while read line; do echo $line; done < log.txt
Correct.
Shell
<a href='https://demo.net' target='_blank'>
<a href='https://demo.net' target='_blank' rel='noopener'>
Add rel for security.
HTML
var x int
var x int
Correct.
Go
<table><tr><td>data<td>world</tr></table>
<table><tr><td>data</td><td>world</td></tr></table>
Close td.
HTML
<center>value</center>
<div style='text-align:center;'>value</div>
Use CSS.
HTML
object Order {{ def main(args: Array[String]) = println("data") }}
object Order {{ def main(args: Array[String]): Unit = println("data") }}
Add return type Unit.
Scala
for (int i=0; i<56; i++) {{}}
for (int i=0; i<56; i++) {{}}
Correct.
Java
type MyType = string | number; let x: MyType = true;
type MyType = string | number; let x: MyType = 'hello';
Type not in union.
TypeScript
switch(foo){{ case 18: break; }}
switch(foo){{ case 18: break; default: break; }}
Add default case.
Java
const int x; x = 5;
const int x = 5;
Const must be initialized.
C++
var x = 5; x = "hello"
var x = "hello"
Type mismatch.
Swift
val c = 'info'
val c = "info"
Double quotes.
Kotlin
$data[40]
if ($data.Count -gt 40) {{ $data[40] }}
Check bounds.
PowerShell
val val = 26; val = 3
var val = 26; val = 3
Use var for reassignment.
Scala
if val = 17:
if val == 17:
Use == for comparison.
Python
if data > 29 print('info')
if data > 29: print('info')
Colon missing after if.
Python
cin >> a;
int a; cin >> a;
Declare variable.
C++
def test(): print('test')
def test(): print('test')
Indent function body.
Python
let x = 12; x += 1;
let mut x = 12; x += 1;
Need mut to modify.
Rust
if (y = 27)
if (y == 27)
Use ==.
Scala
else print('data')
else: print('data')
Colon after else.
Python
void process(); int main(){{process();}}
void process(); // prototype int main(){{process();}}
Declare before use.
C++
<?php // code ?>
<?php // code ?>
Correct.
PHP
list(43)
if length(list) >= 43, list(43), end
Check length.
MATLAB
let bar: Int = 'world'
let bar: String = 'world'
Fix type.
Swift
let count: i32 = "result";
let count: &str = "result";
Type mismatch.
Rust
x <- 5; if (x > 3) print('large')
x <- 5; if (x > 3) print('large')
Correct.
R
b > 67 & z < 43
b > 67 and z < 43
Use 'and' not '&'.
Python
print('message')
print('message')
Correct.
R
match item {{ 1 => {{}} }}
match item {{ 1 => {{}} _ => {{}} }}
Match must be exhaustive.
Rust