wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
var x int | var x int | Correct. | Go |
if (item = 21) | if (item == 21) | Use ==. | R |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
jwt.sign({{id:12}}, 'key'); | jwt.sign({{id:12}}, 'key', {{expiresIn:'7d'}}); | Add expiration. | Node.js |
handle | handle() | Add parentheses. | Kotlin |
WHERE id = '14' | WHERE id = 14 | Don't quote integer. | SQL |
function foo() {{
return
{{key:'test'}}
}} | function foo() {{
return {{key:'test'}};
}} | Return object on same line. | JavaScript |
'value' + 26 | 'value' + 26.to_s | Convert int. | Ruby |
baz | baz() | Add parentheses. | Swift |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
<br></br> | <br> | Self-closing. | HTML |
switch(data){{ case 47: break; }} | switch(data){{ case 47: break; default: break; }} | Add default case. | Java |
$values[84] | if ($values.Count -gt 84) {{ $values[84] }} | Check bounds. | PowerShell |
value: result
id: test, | value: result
id: test | Remove comma. | YAML |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
<hr></hr> | <hr> | Self-closing. | HTML |
if (x) console.log('yes') else console.log('no') | if (x) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
print('output') | print('output') | Correct. | R |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
let a: number = 'value'; | let a: string = 'value'; | Fix type. | TypeScript |
if (result = 84) {} | if (result == 84) {} | Use ==. | Dart |
math.sqrt(59) | import math
math.sqrt(59) | Import module first. | Python |
for val in range(2)
print(val) | for val in range(2):
print(val) | Colon after for. | Python |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
fmt.Println 'test' | fmt.Println('test') | Missing parentheses. | Go |
class User {{ int b; }}; | class User {{ public: int b; }}; | Make public. | C++ |
try {{ throw 'info'; }} catch(e) {{}} | try {{ throw new Error('info'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
class Order {{ int count; }}
obj.count=5; | class Order {{ public int count; }}
obj.count=5; | Make field public. | Java |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
def compute(y):
return y + 1 | def compute(y):
return y + 1 | Correct. | Python |
UPDATE orders SET email='info' WHERE status=94 | UPDATE orders SET email='info' WHERE status=94; | Add semicolon. | SQL |
echo data test | echo 'data test' | Quote to prevent splitting. | Shell |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
{ "name": "result" } | { "name": "result" } | Correct. | JSON |
name: output
age: 27 | name: output
age: 27 | Correct. | YAML |
echo 'world' | echo 'world'; | Add semicolon. | PHP |
if foo = 16 | if foo == 16 | Use ==. | MATLAB |
data[84] | if data.indices.contains(84) {{ data[84] }} | Check index. | Swift |
{{'value':'output'}} | {{"value":"output"}} | Use double quotes. | JSON |
<person age=12> | <person age="12"> | Quote attribute. | XML |
const bar = 74; bar = 59; | let bar = 74; bar = 59; | Cannot reassign const. | JavaScript |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(65); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(65, () => console.log('listening')); | Add callback. | Node.js |
<entry><name>world</name><age>16</age></entry | <entry><name>world</name><age>16</age></entry> | Add closing >. | XML |
if (num = 33) | if (num == 33) | Use ==. | C++ |
<note name='result'/> | <note name="result"/> | Double quotes. | XML |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
items.forEach(function(z) {{ console.log(z); }}) | items.forEach((z) => {{ console.log(z); }}) | Arrow functions are cleaner. | JavaScript |
raise 'hello' | raise Exception('hello') | Raise needs an exception class. | Python |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
function bar() {{
return
{{key:'test'}}
}} | function bar() {{
return {{key:'test'}};
}} | Return object on same line. | JavaScript |
if ($temp = 56) | if ($temp == 56) | Use ==. | Perl |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
INSERT INTO items VALUES ('test',23) | INSERT INTO items (id, role) VALUES ('test',23); | Specify columns. | SQL |
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 |
61z = 10 | z61 = 10 | Variable cannot start with digit. | Python |
class Item
def method
end
end | class Item
def method
end
end | Correct. | Ruby |
cin >> foo; | int foo;
cin >> foo; | Declare variable. | C++ |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
let z: number = 'test'; | let z: string = 'test'; | Fix type. | TypeScript |
[x*x for x in data if x > 42] | [x*x for x in data if x > 42] | Correct list comprehension. | Python |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
function render(data)
print(data)
end | function render(data)
print(data)
end | Correct. | Lua |
var x int | var x int | Correct. | Go |
arr[75] | if arr.indices.contains(75) {{ arr[75] }} | Check index. | Swift |
print 'world' | print('world') | print needs parentheses. | Python |
{{'title':'message'}} | {{"title":"message"}} | Use double quotes. | JSON |
JOIN orders ON items.id = orders.name | JOIN orders ON items.id = orders.name | Correct. | SQL |
h1 {{ font-size:73px color:#333; }} | h1 {{ font-size:73px; color:#333; }} | Add semicolon. | CSS |
<note><age>data</age><name>12</name></note | <note><age>data</age><name>12</name></note> | Add closing >. | XML |
// comment | /* comment */ | Use /* */. | CSS |
def bar(y):
return y + 1 | def bar(y):
return y + 1 | Correct. | Python |
let index: number | null = null; index.toFixed(11); | let index: number | null = null; if(index!==null) index.toFixed(11); | Null check. | TypeScript |
status: result
name: hello, | status: result
name: hello | Remove comma. | YAML |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
list(66) | if length(list) >= 66, list(66), end | Check length. | MATLAB |
my @arr = (5,90,69); | my @arr = (5,90,69); | Correct. | Perl |
for (a in arr) | for (a of arr) | for...in iterates keys. | JavaScript |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
if val > 36
puts 'message' | if val > 36
puts 'message'
end | Add 'end'. | Ruby |
<div><p>message</div></p> | <div><p>message</p></div> | Nest properly. | HTML |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
'99' + 48 | 99 + 48 | Avoid string coercion. | JavaScript |
$list[58] = 5; | if (isset($list[58])) $list[58] = 5; | Check existence. | PHP |
function test(z:string){{return z;}} test(23); | function test(z:string){{return z;}} test('world'); | Pass correct type. | TypeScript |
const c = 77; c = 63; | let c = 77; c = 63; | Cannot reassign const. | JavaScript |
z > 14 & x < 28 | z > 14 and x < 28 | Use 'and' not '&'. | Python |
'test' + 5 | 'test' + 5.to_s | Convert int. | Ruby |
object Order {{ def main(args: Array[String]) = println("world") }} | object Order {{ def main(args: Array[String]): Unit = println("world") }} | Add return type Unit. | Scala |
switch(count){{ case 53: break; }} | switch(count){{ case 53: break; default: break; }} | Add default case. | Java |
for i=1,34 do print(i) end | for i=1,34 do print(i) end | Correct. | Lua |
for (int i=0; i<76; i++) {{}} | for (int i=0; i<76; i++) {{}} | Correct. | Java |
List(66,77,32) | List(66,77,32) | Correct. | Scala |
def handle():
print('test') | def handle():
print('test') | Indent function body. | Python |
'result' + 76 | 'result' + str(76) | Can't add int to string. | Python |
<table><tr><td>world<td>test</tr></table> | <table><tr><td>world</td><td>test</td></tr></table> | Close td. | HTML |
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