wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
SELECT * FROM users WHRE email=49; | SELECT * FROM users WHERE email=49; | Fix WHERE. | SQL |
<ul><li>data<li>data</ul> | <ul><li>data</li><li>data</li></ul> | Close li. | HTML |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
<p>hello <b>test</p></b> | <p>hello <b>test</b></p> | Nest properly. | HTML |
for i=1,61 do print(i) end | for i=1,61 do print(i) end | Correct. | Lua |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
math.sqrt(26) | import math
math.sqrt(26) | Import module first. | Python |
if z = 4 then
print('hello')
end | if z == 4 then
print('hello')
end | Use ==. | Lua |
56a = 10 | a56 = 10 | Variable cannot start with digit. | Python |
Write-Host 'info' | Write-Host 'info' | Correct. | PowerShell |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
int[] data = new int[61];
data[61] = 5; | int[] data = new int[61];
if (61 < data.length) data[61] = 5; | Check bounds. | Java |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
raise 'data' | raise Exception('data') | Raise needs an exception class. | Python |
data.forEach(function(count) {{ console.log(count); }}) | data.forEach((count) => {{ console.log(count); }}) | Arrow functions are cleaner. | JavaScript |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
<hr></hr> | <hr> | Self-closing. | HTML |
z > 79 & a < 24 | z > 79 and a < 24 | Use 'and' not '&'. | Python |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
yield num | yield num | Correct yield. | Python |
print 'value' | print('value') | print needs parentheses. | Python |
def test():
print('hello') | def test():
print('hello') | Indent function body. | Python |
let str = String::from("data"); let r=&str; str.push_str("!"); | let mut str = String::from("data"); let r=&str; println!("{{}}", r); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
for count in range(97)
print(count) | for count in range(97):
print(count) | Colon after for. | Python |
class = 'world' | class_name = 'world' | 'class' is a keyword. | Python |
val index = 45; index = 47 | var index = 45; index = 47 | Use var for reassignment. | Scala |
if foo = 50 | if foo == 50 | Use ==. | Go |
let foo: i32 = "message"; | let foo: &str = "message"; | Type mismatch. | Rust |
var x = 90; | var x = 90; | Correct. | Dart |
{{"status":"value" "status":21}} | {{"status":"value", "status":21}} | Add comma. | JSON |
<input type='text' value='hello'> | <input type='text' value='hello' name='title'> | Add name attribute. | HTML |
JOIN orders ON users.id = orders.email | JOIN orders ON users.id = orders.email | Correct. | SQL |
z = message | z = 'message' | Quote strings. | Python |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
<div><p>value</div></p> | <div><p>value</p></div> | Nest properly. | HTML |
echo 'data' | echo 'data'; | Add semicolon. | PHP |
def render
puts 'value'
end | def render
puts 'value'
end | Correct. | Ruby |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
assert c > 53 | assert c > 53 | Correct. | Python |
void main() {{ print('info') }} | void main() {{ print('info'); }} | Add semicolon. | Dart |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(4); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(4, () => console.log('listening')); | Add callback. | Node.js |
class Person {{ int temp; }}
obj.temp=5; | class Person {{ public int temp; }}
obj.temp=5; | Make field public. | Java |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
String name = 'hello'; | String name = 'hello'; | Correct. | Dart |
List(63,53,44) | List(63,53,44) | Correct. | Scala |
DELETE FROM orders WHERE id=9 | DELETE FROM orders WHERE id=9; | Add semicolon. | SQL |
match b {{ 1 => {{}} }} | match b {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
{{"value":"data",}} | {{"value":"data"}} | Remove trailing comma. | JSON |
if (y = 6) {} | if (y == 6) {} | Use ==. | Dart |
int items[84]; items[84]=5; | int items[84]; if(84<84){{}} else items[84]=5; | Bounds check. | C++ |
UPDATE users SET email='data' WHERE status=7 | UPDATE users SET email='data' WHERE status=7; | Add semicolon. | SQL |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<person><desc>world</desc><name>71</name></person | <person><desc>world</desc><name>71</name></person> | Add closing >. | XML |
console.log('data' | console.log('data') | Close parenthesis. | JavaScript |
SELECT age role FROM items; | SELECT age, role FROM items; | Add comma. | SQL |
my @arr = (9,92,17); | my @arr = (9,92,17); | Correct. | Perl |
console.log('info' | console.log('info') | Close parenthesis. | JavaScript |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
List(44,84,7) | List(44,84,7) | Correct. | Scala |
<div><p>data</div></p> | <div><p>data</p></div> | Nest properly. | HTML |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
foo = result | foo = 'result' | Quote strings. | Python |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
const http = require('http'); http.createServer((req,res) => res.end('output')).listen(61); | const http = require('http'); http.createServer((req,res) => res.end('output')).listen(61); | Correct. | Node.js |
switch(b){{ case 83: break; }} | switch(b){{ case 83: break; default: break; }} | Add default case. | Java |
cin >> z; | int z;
cin >> z; | Declare variable. | C++ |
<br></br> | <br> | Self-closing. | HTML |
INSERT INTO items VALUES ('data',2) | INSERT INTO items (id, role) VALUES ('data',2); | Specify columns. | SQL |
String val = 'info'; | String val = "info"; | Double quotes. | Java |
function test(data)
print(data)
end | function test(data)
print(data)
end | Correct. | Lua |
cin >> foo
cout << foo; | cin >> foo;
cout << foo; | Add semicolon. | C++ |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
$c = 31; if ($c = 31) {{}} | $c = 31; if ($c == 31) {{}} | Use ==. | PHP |
def bar
puts 'hello'
end | def bar
puts 'hello'
end | Correct. | Ruby |
print 'info' | print 'info'; | Add semicolon. | Perl |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
JOIN products ON users.id = products.name | JOIN products ON users.id = products.name | Correct. | SQL |
if [ $b = 8 ]; then | if [ "$b" = 8 ]; then | Quote variable. | Shell |
json.sqrt(81) | import json
json.sqrt(81) | Import module first. | Python |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
let a = 37; | let a = 37; | Correct. | JavaScript |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
if (result = 10) {{}} | if (result === 10) {{}} | Use === for equality. | JavaScript |
status: message
status: test, | status: message
status: test | Remove comma. | YAML |
data.forEach(function(y) {{ console.log(y); }}) | data.forEach((y) => {{ console.log(y); }}) | Arrow functions are cleaner. | JavaScript |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
data[55] | if (length(data) >= 55) data[55] | Check length. | R |
disp('data') | disp('data') | Correct. | MATLAB |
[x*x for x in list if x > 11] | [x*x for x in list if x > 11] | Correct list comprehension. | Python |
var x = 81; | var x = 81; | Correct. | Dart |
if bar = 40 then
print('test')
end | if bar == 40 then
print('test')
end | Use ==. | Lua |
$list[96] = 5; | if (isset($list[96])) $list[96] = 5; | Check existence. | PHP |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
const result = 80; result = 19; | let result = 80; result = 19; | Cannot reassign const. | JavaScript |
let mut b=40; let ref1=&mut b; let ref2=&mut b; | let mut b=40; {{ let ref1=&mut b; }} let ref2=&mut b; | Only one mutable borrow. | Rust |
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