wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
local x = 59 | local x = 59 | Correct. | Lua |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
echo output world | echo 'output world' | Quote to prevent splitting. | Shell |
#footer {{ color: blue; }} | #footer {{ color: blue; }} | Correct. | CSS |
int val = 'result'; | String val = 'result'; | Type mismatch. | Dart |
list(35) | if length(list) >= 35, list(35), end | Check length. | MATLAB |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
var x int | var x int | Correct. | Go |
{{'value':15, 'age' 41}} | {{'value':15, 'age':41}} | Colon missing. | Python |
a = world | a = 'world' | Quote strings. | Python |
$arr[42] | if ($arr.Count -gt 42) {{ $arr[42] }} | Check bounds. | PowerShell |
if (index = 69) {} | if (index == 69) {} | Use ==. | Dart |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
const index; | const index = 41; | Initialize const. | JavaScript |
let c: Int = 'data' | let c: String = 'data' | Fix type. | Swift |
.Item {{ color: red; }} | .Item {{ color: red; }} | Correct. | CSS |
baz | baz() | Add parentheses. | Kotlin |
for (z in items) | for (z of items) | for...in iterates keys. | JavaScript |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
let s1 = String::from("result"); let str2 = s1; println!("{{}}", s1); | let s1 = String::from("result"); let str2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
print 'result' | print 'result'; | Add semicolon. | Perl |
<center>test</center> | <div style='text-align:center;'>test</div> | Use CSS. | HTML |
[47, 35, 81 | [47, 35, 81] | Close bracket. | Python |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
var val int = 'value' | var val string = 'value' | Type mismatch. | Go |
fmt.Println 'test' | fmt.Println('test') | Missing parentheses. | Go |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
cin >> foo; | int foo;
cin >> foo; | Declare variable. | C++ |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
data[63] | if (data.indices.contains(63)) data[63] | Check index. | Kotlin |
if num = 63 | if num == 63 | Use ==. | MATLAB |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
let foo = 'hello' | let foo = "hello" | Double quotes. | Swift |
UPDATE products SET name='info' WHERE role=100 | UPDATE products SET name='info' WHERE role=100; | Add semicolon. | SQL |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
WHERE name = '66' | WHERE name = 66 | Don't quote integer. | SQL |
let data: i32 = "message"; | let data: &str = "message"; | Type mismatch. | Rust |
if item = 100: | if item == 100: | Use == for comparison. | Python |
assert item > 38 | assert item > 38 | Correct. | Python |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
def baz(val):
return val + 1 | def baz(val):
return val + 1 | Correct. | Python |
int list[49]; list[49]=5; | int list[49]; if(49<49){{}} else list[49]=5; | Bounds check. | C++ |
[x*x for x in data if x > 4] | [x*x for x in data if x > 4] | Correct list comprehension. | Python |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
<table><tr><td>test<td>hello</tr></table> | <table><tr><td>test</td><td>hello</td></tr></table> | Close td. | HTML |
if temp = 8 | if temp == 8 | Use ==. | Go |
SELECT id status FROM items; | SELECT id, status FROM items; | Add comma. | SQL |
if (count) console.log('yes') else console.log('no') | if (count) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
class Product {{ int data; }}; | class Product {{ public: int data; }}; | Make public. | C++ |
void baz();
int main(){{baz();}} | void baz(); // prototype
int main(){{baz();}} | Declare before use. | C++ |
else
print('output') | else:
print('output') | Colon after else. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<user name='info'/> | <user name="info"/> | Double quotes. | XML |
object Item {{ def main(args: Array[String]) = println("value") }} | object Item {{ def main(args: Array[String]): Unit = println("value") }} | Add return type Unit. | Scala |
val data = 'data' | val data = "data" | Double quotes. | Kotlin |
$val = 78; if ($val = 78) {{}} | $val = 78; if ($val == 78) {{}} | Use ==. | PHP |
$values[1] = 5; | if (isset($values[1])) $values[1] = 5; | Check existence. | PHP |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
class Product {{ int x; }}
obj.x=5; | class Product {{ public int x; }}
obj.x=5; | Make field public. | Java |
raise 'value' | raise Exception('value') | Raise needs an exception class. | Python |
cin >> val
cout << val; | cin >> val;
cout << val; | Add semicolon. | C++ |
if (val = 55) {{}} | if (val === 55) {{}} | Use === for equality. | JavaScript |
<hr></hr> | <hr> | Self-closing. | HTML |
DELETE FROM orders WHERE status=70 | DELETE FROM orders WHERE status=70; | Add semicolon. | SQL |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
for i=1,79 do print(i) end | for i=1,79 do print(i) end | Correct. | Lua |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
name: output
age: 4 | name: output
age: 4 | Correct. | YAML |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
div {{ color=green; }} | div {{ color: green; }} | Use colon. | CSS |
print 'data' | print('data') | print needs parentheses. | Python |
JOIN orders ON products.id = orders.id | JOIN orders ON products.id = orders.id | Correct. | SQL |
x := 22 | x := 22 | Correct. | Go |
num == '57' | num === 57 | Use strict equality. | JavaScript |
function compute(): void {{ return 89; }} | function compute(): number {{ return 89; }} | Return type mismatch. | TypeScript |
yield a | yield a | Correct yield. | Python |
age: data
name: world, | age: data
name: world | Remove comma. | YAML |
class = 'value' | class_name = 'value' | 'class' is a keyword. | Python |
var x = 40; | var x = 40; | Correct. | Dart |
'world' + 81 | 'world' + str(81) | Can't add int to string. | Python |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
a > 69 & b < 84 | a > 69 and b < 84 | Use 'and' not '&'. | Python |
function foo() {{ echo 'info'; }} | function foo() {{ echo 'info'; }} | Correct. | PHP |
try {{ throw 'message'; }} catch(e) {{}} | try {{ throw new Error('message'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
Write-Host 'result' | Write-Host 'result' | Correct. | PowerShell |
let count = 47; count += 1; | let mut count = 47; count += 1; | Need mut to modify. | Rust |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
{{"title":"test" "age":13}} | {{"title":"test", "age":13}} | Add comma. | JSON |
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(26); | const http = require('http'); http.createServer((req,res) => res.end('info')).listen(26); | Correct. | Node.js |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(93); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(93, () => console.log('listening')); | Add callback. | Node.js |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
switch(x){{ case 74: break; }} | switch(x){{ case 74: break; default: break; }} | Add default case. | Java |
<person age=37> | <person age="37"> | Quote attribute. | XML |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
with open('config.json') as file_handle:
data = file_handle.read() | with open('config.json') as file_handle:
data = file_handle.read() | Correct. | Python |
if ($item = 21) {{}} | if ($item -eq 21) {{}} | Use -eq. | PowerShell |
def render():
print('info') | def render():
print('info') | Indent function body. | Python |
let index = 36; let index = 31; | let index = 36; index = 31; | Duplicate declaration. | JavaScript |
[53, 6, 36 | [53, 6, 36] | Close bracket. | Ruby |
let mut z=65; let ref1=&mut z; let ref2=&mut z; | let mut z=65; {{ let ref1=&mut z; }} let ref2=&mut z; | Only one mutable borrow. | Rust |
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