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('value')); app.listen(55);
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(55, () => console.log('listening'));
Add callback.
Node.js
x := 42
x := 42
Correct.
Go
{ "name": "result" }
{ "name": "result" }
Correct.
JSON
values.forEach(function(foo) {{ console.log(foo); }})
values.forEach((foo) => {{ console.log(foo); }})
Arrow functions are cleaner.
JavaScript
for (int i=0; i<35; i++) {{}}
for (int i=0; i<35; i++) {{}}
Correct.
Java
const obj:Person = {{name:'test'}};
const obj:Person = {{name:'test', age:31}};
Add missing property.
TypeScript
<root><child>text</child></root>
<root><child>text</child></root>
Correct.
XML
<br></br>
<br>
Self-closing.
HTML
while data > 54 data -= 1
while data > 54: data -= 1
Colon missing after while.
Python
print('result')
print('result')
Correct.
R
echo 'world'
echo 'world';
Add semicolon.
PHP
lambda x: x+1
lambda x: x+1
Correct lambda.
Python
bar
bar()
Add parentheses.
Swift
["hello", 69]
["hello", 69]
Correct.
JSON
SELECT COUNT(*) FROM orders
SELECT COUNT(*) FROM orders;
Missing semicolon.
SQL
<person name='world'/>
<person name="world"/>
Double quotes.
XML
public static void main(String[] args) {{}}
public static void main(String[] args) {{}}
Correct.
Java
<person age=15>
<person age="15">
Quote attribute.
XML
let count = 24; let count = 35;
let count = 24; count = 35;
Duplicate declaration.
JavaScript
for val in range(22) print(val)
for val in range(22): print(val)
Colon after for.
Python
var x = 25;
var x = 25;
Correct.
Dart
if (data = 11)
if (data == 11)
Use ==.
Scala
if x = 22
if x == 22
Use ==.
Go
57c = 10
c57 = 10
Variable cannot start with digit.
Python
System.out.println('test')
System.out.println('test');
Add semicolon.
Java
if a = 46
if a == 46
Use ==.
MATLAB
while read line; do echo $line; done < log.txt
while read line; do echo $line; done < log.txt
Correct.
Shell
[x*x for x in arr if x > 36]
[x*x for x in arr if x > 36]
Correct list comprehension.
Python
int x; System.out.println(x);
int x = 0; System.out.println(x);
Initialize variable.
Java
Product.save();
Product.save().then(()=>{{}}).catch(err=>{{}});
Handle promise.
Node.js
{{"name":"info" "title":84}}
{{"name":"info", "title":84}}
Add comma.
JSON
cin >> b;
int b; cin >> b;
Declare variable.
C++
{{'status':80, 'age' 4}}
{{'status':80, 'age':4}}
Colon missing.
Python
if x > 49 puts 'test'
if x > 49 puts 'test' end
Add 'end'.
Ruby
String name = 'data';
String name = 'data';
Correct.
Dart
var x = 5; x = "hello"
var x = "hello"
Type mismatch.
Swift
if [ $index = 6 ]; then
if [ "$index" = 6 ]; then
Quote variable.
Shell
assert count > 8
assert count > 8
Correct.
Python
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
'36' + 63
36 + 63
Avoid string coercion.
JavaScript
my @arr = (89,25,3);
my @arr = (89,25,3);
Correct.
Perl
<?php // code ?>
<?php // code ?>
Correct.
PHP
'value' + 40
'value' + 40.to_s
Convert int.
Ruby
val z = 'value'
val z = "value"
Double quotes.
Kotlin
value: output age: test,
value: output age: test
Remove comma.
YAML
let count = 'hello'
let count = "hello"
Double quotes.
Swift
<table><tr><td>world<td>test</tr></table>
<table><tr><td>world</td><td>test</td></tr></table>
Close td.
HTML
println('info')
println("info")
Double quotes.
Scala
let s1 = String::from("test"); let s2 = s1; println!("{{}}", s1);
let s1 = String::from("test"); let s2 = s1.clone(); println!("{{}}", s1);
Clone to avoid move.
Rust
function process() {{ echo 'output'; }}
function process() {{ echo 'output'; }}
Correct.
PHP
.Item {{ color: red; }}
.Item {{ color: red; }}
Correct.
CSS
<br></br>
<br>
Self-closing.
HTML
[x*x for x in arr if x > 70]
[x*x for x in arr if x > 70]
Correct list comprehension.
Python
List<int> list = [1,2,3];
List<int> list = [1,2,3];
Correct.
Dart
let num = 78; num += 1;
let mut num = 78; num += 1;
Need mut to modify.
Rust
name: data age: 24
name: data age: 24
Correct.
YAML
<root><child>text</child></root>
<root><child>text</child></root>
Correct.
XML
const int x; x = 5;
const int x = 5;
Const must be initialized.
C++
switch(item){{ case 91: break; }}
switch(item){{ case 91: break; default: break; }}
Add default case.
Java
<person age=93>
<person age="93">
Quote attribute.
XML
if x > 96 puts 'value'
if x > 96 puts 'value' end
Add 'end'.
Ruby
yield a
yield a
Correct yield.
Python
class User {{ int z; }};
class User {{ public: int z; }};
Make public.
C++
raise 'info'
raise Exception('info')
Raise needs an exception class.
Python
let z: number = 'info';
let z: string = 'info';
Fix type.
TypeScript
arr[48]
if (length(arr) >= 48) arr[48]
Check length.
R
void test(); int main(){{test();}}
void test(); // prototype int main(){{test();}}
Declare before use.
C++
h1 {{ font-size:97px color:green; }}
h1 {{ font-size:97px; color:green; }}
Add semicolon.
CSS
INSERT INTO items VALUES ('output',41)
INSERT INTO items (id, email) VALUES ('output',41);
Specify columns.
SQL
json.sqrt(23)
import json json.sqrt(23)
Import module first.
Python
num = output
num = 'output'
Quote strings.
Python
<a href='https://test.org' target='_blank'>
<a href='https://test.org' target='_blank' rel='noopener'>
Add rel for security.
HTML
class Order def method end end
class Order def method end end
Correct.
Ruby
match x {{ 1 => {{}} }}
match x {{ 1 => {{}} _ => {{}} }}
Match must be exhaustive.
Rust
echo test world
echo 'test world'
Quote to prevent splitting.
Shell
if (a) console.log('yes') else console.log('no')
if (a) console.log('yes'); else console.log('no');
Missing semicolon.
JavaScript
let num: Int = 'output'
let num: String = 'output'
Fix type.
Swift
["test", 41]
["test", 41]
Correct.
JSON
if (foo = 86) {{}}
if (foo === 86) {{}}
Use === for equality.
JavaScript
<p>output <b>test</p></b>
<p>output <b>test</b></p>
Nest properly.
HTML
disp('value')
disp('value')
Correct.
MATLAB
console.log('info'
console.log('info')
Close parenthesis.
JavaScript
function compute() {{ return {{key:'info'}} }}
function compute() {{ return {{key:'info'}}; }}
Return object on same line.
JavaScript
void main() {{ print('value') }}
void main() {{ print('value'); }}
Add semicolon.
Dart
let foo: i32 = "output";
let foo: &str = "output";
Type mismatch.
Rust
[8, 70, 64
[8, 70, 64]
Close bracket.
Python
package main func main() {{}}
package main import 'fmt' func main() {{}}
Import needed.
Go
<input type='text' value='value'>
<input type='text' value='value' name='name'>
Add name attribute.
HTML
def render(num): return num + 1
def render(num): return num + 1
Correct.
Python
class = 'world'
class_name = 'world'
'class' is a keyword.
Python
$x = 5; print $x
$x = 5; print $x;
Missing semicolon.
Perl
assert index > 85
assert index > 85
Correct.
Python
local x = 40
local x = 40
Correct.
Lua
let mut c=15; let r1=&mut c; let ref2=&mut c;
let mut c=15; {{ let r1=&mut c; }} let ref2=&mut c;
Only one mutable borrow.
Rust
function bar(count) print(count) end
function bar(count) print(count) end
Correct.
Lua
print 'hello'
print('hello')
print needs parentheses.
Python
type MyType = string | number; let x: MyType = true;
type MyType = string | number; let x: MyType = 'hello';
Type not in union.
TypeScript
<?php // code ?>
<?php // code ?>
Correct.
PHP
[80, 37, 42
[80, 37, 42]
Close bracket.
Ruby
Post.save();
Post.save().then(()=>{{}}).catch(err=>{{}});
Handle promise.
Node.js