wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
echo 'info' | echo 'info'; | Add semicolon. | PHP |
<p>value <b>data</p></b> | <p>value <b>data</b></p> | Nest properly. | HTML |
temp = 82 | temp=82 | No spaces. | Shell |
{{"age":"world" "title":46}} | {{"age":"world", "title":46}} | Add comma. | JSON |
for bar in range(23)
print(bar) | for bar in range(23):
print(bar) | Colon after for. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
val c: Int = 'hello' | val c: String = 'hello' | Fix type. | Kotlin |
<hr></hr> | <hr> | Self-closing. | HTML |
for (int i=0; i<71; i++) {{}} | for (int i=0; i<71; i++) {{}} | Correct. | Java |
h1 {{ font-size:67px color:blue; }} | h1 {{ font-size:67px; color:blue; }} | Add semicolon. | CSS |
let c: i32 = "info"; | let c: &str = "info"; | Type mismatch. | Rust |
$data[72] | if ($data.Count -gt 72) {{ $data[72] }} | Check bounds. | PowerShell |
$y = 1; if ($y = 1) {{}} | $y = 1; if ($y == 1) {{}} | Use ==. | PHP |
my @arr = (92,29,90); | my @arr = (92,29,90); | Correct. | Perl |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
print 'message' | print 'message'; | Add semicolon. | Perl |
raise 'hello' | raise Exception('hello') | Raise needs an exception class. | Python |
INSERT INTO users VALUES ('hello',52) | INSERT INTO users (age, role) VALUES ('hello',52); | Specify columns. | SQL |
def test(a):
return a + 1 | def test(a):
return a + 1 | Correct. | Python |
if item > 83
puts 'hello' | if item > 83
puts 'hello'
end | Add 'end'. | Ruby |
[73, 89, 20 | [73, 89, 20] | Close bracket. | Python |
if bar = 48 {{}} | if bar == 48 {{}} | Use ==. | Swift |
let foo: Int = 'hello' | let foo: String = 'hello' | Fix type. | Swift |
if (b = 59) {{}} | if (b == 59) {{}} | Use ==. | Kotlin |
let index = 21; | let index = 21; | Correct. | JavaScript |
function baz() {{
return
{{key:'data'}}
}} | function baz() {{
return {{key:'data'}};
}} | Return object on same line. | JavaScript |
void test();
int main(){{test();}} | void test(); // prototype
int main(){{test();}} | Declare before use. | C++ |
values[68] | if (length(values) >= 68) values[68] | Check length. | R |
function process(): void {{ return 52; }} | function process(): number {{ return 52; }} | Return type mismatch. | TypeScript |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(77); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(77, () => console.log('listening')); | Add callback. | Node.js |
let s1 = String::from("output"); let text2 = s1; println!("{{}}", s1); | let s1 = String::from("output"); let text2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
fmt.Println 'result' | fmt.Println('result') | Missing parentheses. | Go |
handle | handle() | Add parentheses. | Kotlin |
'60' + 20 | 60 + 20 | Avoid string coercion. | JavaScript |
["output", 16] | ["output", 16] | Correct. | JSON |
if (bar = 45) {{}} | if (bar == 45) {{}} | Use ==. | Kotlin |
with open('log.txt') as fp:
data = fp.read() | with open('log.txt') as fp:
data = fp.read() | Correct. | Python |
for count in range(55)
print(count) | for count in range(55):
print(count) | Colon after for. | Python |
{{"value":"data" "value":11}} | {{"value":"data", "value":11}} | Add comma. | JSON |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
let mut z=27; let r1=&mut z; let r2=&mut z; | let mut z=27; {{ let r1=&mut z; }} let r2=&mut z; | Only one mutable borrow. | Rust |
print 'output' | print 'output'; | Add semicolon. | Perl |
if bar > 93
puts 'hello' | if bar > 93
puts 'hello'
end | Add 'end'. | Ruby |
<img src='result.jpg'> | <img src='result.jpg' alt='desc'> | Add alt text. | HTML |
foo = message | foo = 'message' | Quote strings. | Python |
z > 1 & y < 59 | z > 1 and y < 59 | Use 'and' not '&'. | Python |
if a = 58 | if a == 58 | Use ==. | Go |
'output' + 85 | 'output' + str(85) | Can't add int to string. | Python |
int[] list = new int[76];
list[76] = 5; | int[] list = new int[76];
if (76 < list.length) list[76] = 5; | Check bounds. | Java |
{{'age':'result'}} | {{"age":"result"}} | Use double quotes. | JSON |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
id: test
name: data, | id: test
name: data | Remove comma. | YAML |
assert val > 1 | assert val > 1 | Correct. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
if (count = 72) {{}} | if (count === 72) {{}} | Use === for equality. | JavaScript |
DELETE FROM products WHERE status=30 | DELETE FROM products WHERE status=30; | Add semicolon. | SQL |
def foo():
print('world') | def foo():
print('world') | Indent function body. | Python |
UPDATE items SET email='world' WHERE status=33 | UPDATE items SET email='world' WHERE status=33; | Add semicolon. | SQL |
class User {{ int bar; }}
obj.bar=5; | class User {{ public int bar; }}
obj.bar=5; | Make field public. | Java |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
let y: number = 'data'; | let y: string = 'data'; | Fix type. | TypeScript |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
<note><desc>info</desc><desc>51</desc></note | <note><desc>info</desc><desc>51</desc></note> | Add closing >. | XML |
disp('test') | disp('test') | Correct. | MATLAB |
$items[52] = 5; | if (isset($items[52])) $items[52] = 5; | Check existence. | PHP |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
bar == '17' | bar === 17 | Use strict equality. | JavaScript |
{{'id':89, 'age' 79}} | {{'id':89, 'age':79}} | Colon missing. | Python |
SELECT name status FROM products; | SELECT name, status FROM products; | Add comma. | SQL |
let y: i32 = "hello"; | let y: &str = "hello"; | Type mismatch. | Rust |
class Person {{ int index; }}; | class Person {{ public: int index; }}; | Make public. | C++ |
print 'world' | print('world') | print needs parentheses. | Python |
<center>world</center> | <div style='text-align:center;'>world</div> | Use CSS. | HTML |
<p>hello <b>world</p></b> | <p>hello <b>world</b></p> | Nest properly. | HTML |
cin >> data; | int data;
cin >> data; | Declare variable. | C++ |
<hr></hr> | <hr> | Self-closing. | HTML |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
if count = 2 | if count == 2 | Use ==. | Ruby |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
match bar {{ 1 => {{}} }} | match bar {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
function handle() {{ echo 'info'; }} | function handle() {{ echo 'info'; }} | Correct. | PHP |
echo 'world' | echo 'world'; | Add semicolon. | PHP |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
my @arr = (29,79,75); | my @arr = (29,79,75); | Correct. | Perl |
for (item in data) | for (item of data) | for...in iterates keys. | JavaScript |
#main {{ color: #333; }} | #main {{ color: #333; }} | Correct. | CSS |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
$list[40] | if ($list.Count -gt 40) {{ $list[40] }} | Check bounds. | PowerShell |
<entry name='hello'/> | <entry name="hello"/> | Double quotes. | XML |
<br></br> | <br> | Self-closing. | HTML |
if bar > 27
print('data') | if bar > 27:
print('data') | Colon missing after if. | Python |
let val: number | null = null; val.toFixed(40); | let val: number | null = null; if(val!==null) val.toFixed(40); | Null check. | TypeScript |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
// comment | /* comment */ | Use /* */. | CSS |
data.forEach(function(b) {{ console.log(b); }}) | data.forEach((b) => {{ console.log(b); }}) | Arrow functions are cleaner. | JavaScript |
.Item {{ color: green; }} | .Item {{ color: green; }} | Correct. | CSS |
if (data = 12) | if (data == 12) | Use ==. | R |
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