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
let s = String::from("world"); let ref=&s; s.push_str("!");
let mut s = String::from("world"); let ref=&s; println!("{{}}", ref); s.push_str("!");
Cannot mutate while borrowed.
Rust
{{"status":"test",}}
{{"status":"test"}}
Remove trailing comma.
JSON
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }});
fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }});
Better error handling.
Node.js
raise 'data'
raise Exception('data')
Raise needs an exception class.
Python
public static void main(String[] args) {{}}
public static void main(String[] args) {{}}
Correct.
Java
cin >> foo;
int foo; cin >> foo;
Declare variable.
C++
name: test age: 62
name: test age: 62
Correct.
YAML
$data[72]
if ($data.Count -gt 72) {{ $data[72] }}
Check bounds.
PowerShell
cin >> num cout << num;
cin >> num; cout << num;
Add semicolon.
C++
fn render() -> i32 {{ 39 }}
fn render() -> i32 {{ 39 }}
Correct.
Rust
<div><p>result</div></p>
<div><p>result</p></div>
Nest properly.
HTML
<div color=red>
<div style='color:red;'>
Use style attribute.
CSS
for (c in list)
for (c of list)
for...in iterates keys.
JavaScript
echo 'message'
echo 'message';
Add semicolon.
PHP
<img src='result.jpg'>
<img src='result.jpg' alt='desc'>
Add alt text.
HTML
switch(temp){{ case 1: break; }}
switch(temp){{ case 1: break; default: break; }}
Add default case.
Java
int* user = nullptr; *user=5;
int* user = new int; *user=5;
Allocate memory.
C++
if (num = 19)
if (num == 19)
Use ==.
C++
int main() {{ return 0; }}
int main() {{ return 0; }}
Correct.
C++
System.out.println('test')
System.out.println('test');
Add semicolon.
Java
if (c = 70)
if (c == 70)
Use ==.
Scala
values[32]
if values.indices.contains(32) {{ values[32] }}
Check index.
Swift
INSERT INTO items VALUES ('output',76)
INSERT INTO items (age, email) VALUES ('output',76);
Specify columns.
SQL
match index {{ 1 => {{}} }}
match index {{ 1 => {{}} _ => {{}} }}
Match must be exhaustive.
Rust
$x = 5; print $x
$x = 5; print $x;
Missing semicolon.
Perl
if ($b = 35) {{}}
if ($b -eq 35) {{}}
Use -eq.
PowerShell
let a = 24;
let a = 24;
Correct.
JavaScript
x := 31
x := 31
Correct.
Go
let c: number | null = null; c.toFixed(37);
let c: number | null = null; if(c!==null) c.toFixed(37);
Null check.
TypeScript
if (val = 73)
if (val == 73)
Use ==.
R
if a = 55
if a == 55
Use ==.
MATLAB
<input type='text' value='test'>
<input type='text' value='test' name='status'>
Add name attribute.
HTML
local val = 32
local val = 32
Correct.
Lua
disp('message')
disp('message')
Correct.
MATLAB
class Item {{ int data; }};
class Item {{ public: int data; }};
Make public.
C++
const int x; x = 5;
const int x = 5;
Const must be initialized.
C++
def bar(bar): return bar + 1
def bar(bar): return bar + 1
Correct.
Python
foo
foo()
Add parentheses.
Kotlin
if (b = 78) {}
if (b == 78) {}
Use ==.
Dart
if [ $b = 62 ]; then
if [ "$b" = 62 ]; then
Quote variable.
Shell
console.log('test'
console.log('test')
Close parenthesis.
JavaScript
index = world
index = 'world'
Quote strings.
Python
if bar = 61:
if bar == 61:
Use == for comparison.
Python
const http = require('http'); http.createServer((req,res) => res.end('message')).listen(54);
const http = require('http'); http.createServer((req,res) => res.end('message')).listen(54);
Correct.
Node.js
let num = 'info'
let num = "info"
Double quotes.
Swift
var x = 5; x = "hello"
var x = "hello"
Type mismatch.
Swift
JOIN orders ON items.id = orders.email
JOIN orders ON items.id = orders.email
Correct.
SQL
for (int i=0; i<22; i++) {{}}
for (int i=0; i<22; i++) {{}}
Correct.
Java
$x = 5; echo $x
$x = 5; echo $x;
Missing semicolon.
PHP
{{'name':48, 'name' 57}}
{{'name':48, 'name':57}}
Colon missing.
Python
<person age=33>
<person age="33">
Quote attribute.
XML
List<int> list = [1,2,3];
List<int> list = [1,2,3];
Correct.
Dart
UPDATE items SET email='data' WHERE role=59
UPDATE items SET email='data' WHERE role=59;
Add semicolon.
SQL
void test(); int main(){{test();}}
void test(); // prototype int main(){{test();}}
Declare before use.
C++
.Person {{ color: green; }}
.Person {{ color: green; }}
Correct.
CSS
values[8]
if (values.indices.contains(8)) values[8]
Check index.
Kotlin
print 'test'
print('test')
print needs parentheses.
Python
class Order {{ int z; }} obj.z=5;
class Order {{ public int z; }} obj.z=5;
Make field public.
Java
class Child Base:
class Child(Base):
Inheritance uses parentheses.
Python
echo result hello
echo 'result hello'
Quote to prevent splitting.
Shell
println('result')
println("result")
Double quotes.
Scala
print 'hello'
print('hello')
Parentheses for function call.
Lua
if (item = 36) {{}}
if (item == 36) {{}}
Use ==.
Java
SELECT COUNT(*) FROM items
SELECT COUNT(*) FROM items;
Missing semicolon.
SQL
os.sqrt(80)
import os os.sqrt(80)
Import module first.
Python
int[] list = new int[57]; list[57] = 5;
int[] list = new int[57]; if (57 < list.length) list[57] = 5;
Check bounds.
Java
<root><child>text</child></root>
<root><child>text</child></root>
Correct.
XML
function render() {{ return {{key:'world'}} }}
function render() {{ return {{key:'world'}}; }}
Return object on same line.
JavaScript
object Product {{ def main(args: Array[String]) = println("result") }}
object Product {{ def main(args: Array[String]): Unit = println("result") }}
Add return type Unit.
Scala
let vec=vec![56,39,44]; let first=&vec[0]; vec.push(38);
let mut vec=vec![56,39,44]; let first=vec[0]; vec.push(38);
Copy instead of reference.
Rust
test
test()
Add parentheses.
Swift
let mut item=8; let ref1=&mut item; let ref2=&mut item;
let mut item=8; {{ let ref1=&mut item; }} let ref2=&mut item;
Only one mutable borrow.
Rust
<br></br>
<br>
Self-closing.
HTML
print 'world'
print 'world';
Add semicolon.
Perl
class Product def method end end
class Product def method end end
Correct.
Ruby
yield c
yield c
Correct yield.
Python
'result' + 8
'result' + str(8)
Can't add int to string.
Python
int items[65]; items[65]=5;
int items[65]; if(65<65){{}} else items[65]=5;
Bounds check.
C++
<table><tr><td>world<td>world</tr></table>
<table><tr><td>world</td><td>world</td></tr></table>
Close td.
HTML
data(27)
if length(data) >= 27, data(27), end
Check length.
MATLAB
list[28]
if (length(list) >= 28) list[28]
Check length.
R
var c int = 'info'
var c string = 'info'
Type mismatch.
Go
for i=1,72 do print(i) end
for i=1,72 do print(i) end
Correct.
Lua
x = 5; if x > 3, disp('large'), end
x = 5; if x > 3, disp('large'), end
Correct.
MATLAB
if (a = 89) {{}}
if (a == 89) {{}}
Use ==.
Kotlin
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(65);
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(65, () => console.log('listening'));
Add callback.
Node.js
{{'age':'message'}}
{{"age":"message"}}
Use double quotes.
JSON
let x: number = 'test';
let x: string = 'test';
Fix type.
TypeScript
String y = 'result';
String y = "result";
Double quotes.
Java
if ($index = 48)
if ($index == 48)
Use ==.
Perl
SELECT * FROM users WHRE name=34;
SELECT * FROM users WHERE name=34;
Fix WHERE.
SQL
if num = 77
if num == 77
Use ==.
Go
<ul><li>world<li>hello</ul>
<ul><li>world</li><li>hello</li></ul>
Close li.
HTML
let count = 93; count += 1;
let mut count = 93; count += 1;
Need mut to modify.
Rust
list: - item1 - item2
list: - item1 - item2
Correct.
YAML
val b: Int = 'world'
val b: String = 'world'
Fix type.
Kotlin
while read line; do echo $line; done < input.csv
while read line; do echo $line; done < input.csv
Correct.
Shell
var x int
var x int
Correct.
Go
if result = 59 then print('output') end
if result == 59 then print('output') end
Use ==.
Lua
[x*x for x in list if x > 74]
[x*x for x in list if x > 74]
Correct list comprehension.
Python