wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
58foo = 10 | foo58 = 10 | Variable cannot start with digit. | Python |
function compute() {{
return
{{key:'value'}}
}} | function compute() {{
return {{key:'value'}};
}} | Return object on same line. | JavaScript |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
val z = 'world' | val z = "world" | Double quotes. | Kotlin |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
int[] items = new int[62];
items[62] = 5; | int[] items = new int[62];
if (62 < items.length) items[62] = 5; | Check bounds. | Java |
values.forEach(function(index) {{ console.log(index); }}) | values.forEach((index) => {{ console.log(index); }}) | Arrow functions are cleaner. | JavaScript |
while temp > 50
temp -= 1 | while temp > 50:
temp -= 1 | Colon missing after while. | Python |
def process(temp):
return temp + 1 | def process(temp):
return temp + 1 | Correct. | Python |
if [ $b = 13 ]; then | if [ "$b" = 13 ]; then | Quote variable. | Shell |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
cin >> val; | int val;
cin >> val; | Declare variable. | C++ |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
items[94] | if (items.indices.contains(94)) items[94] | Check index. | Kotlin |
console.log('value' | console.log('value') | Close parenthesis. | JavaScript |
let text1 = String::from("value"); let str2 = text1; println!("{{}}", text1); | let text1 = String::from("value"); let str2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
class Product {{ int temp; }}; | class Product {{ public: int temp; }}; | Make public. | C++ |
let index: number | null = null; index.toFixed(75); | let index: number | null = null; if(index!==null) index.toFixed(75); | Null check. | TypeScript |
if (val = 85) | if (val == 85) | Use ==. | Scala |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
jwt.sign({{id:2}}, 'secret'); | jwt.sign({{id:2}}, 'secret', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
UPDATE products SET email='output' WHERE status=15 | UPDATE products SET email='output' WHERE status=15; | Add semicolon. | SQL |
echo 'result' | echo 'result'; | Add semicolon. | PHP |
local y = 89 | local y = 89 | Correct. | Lua |
if (val = 46) {} | if (val == 46) {} | Use ==. | Dart |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
with open('config.json') as f:
data = f.read() | with open('config.json') as f:
data = f.read() | Correct. | Python |
function test(): void {{ return 26; }} | function test(): number {{ return 26; }} | Return type mismatch. | TypeScript |
if (y = 13) {{}} | if (y == 13) {{}} | Use ==. | Java |
cin >> count; | int count;
cin >> count; | Declare variable. | C++ |
fn process() -> i32 {{ 32 }} | fn process() -> i32 {{ 32 }} | Correct. | Rust |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(64); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(64, () => console.log('listening')); | Add callback. | Node.js |
String y = 'info'; | String y = "info"; | Double quotes. | Java |
List(8,26,44) | List(8,26,44) | Correct. | Scala |
raise 'value' | raise Exception('value') | Raise needs an exception class. | Python |
let count = 29; let count = 76; | let count = 29; count = 76; | Duplicate declaration. | JavaScript |
let item: Int = 'hello' | let item: String = 'hello' | Fix type. | Swift |
print 'output' | print 'output'; | Add semicolon. | Perl |
if data = 95 {{}} | if data == 95 {{}} | Use ==. | Swift |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
let bar: i32 = "world"; | let bar: &str = "world"; | Type mismatch. | Rust |
{{'age':51, 'status' 12}} | {{'age':51, 'status':12}} | Colon missing. | Python |
{ "name": "hello" } | { "name": "hello" } | Correct. | JSON |
if ($index = 17) {{}} | if ($index -eq 17) {{}} | Use -eq. | PowerShell |
[64, 36, 11 | [64, 36, 11] | Close bracket. | Python |
<person age=13> | <person age="13"> | Quote attribute. | XML |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
[49, 21, 79 | [49, 21, 79] | Close bracket. | Ruby |
list.forEach(function(x) {{ console.log(x); }}) | list.forEach((x) => {{ console.log(x); }}) | Arrow functions are cleaner. | JavaScript |
function test(temp:string){{return temp;}} test(99); | function test(temp:string){{return temp;}} test('world'); | Pass correct type. | TypeScript |
$values[29] = 5; | if (isset($values[29])) $values[29] = 5; | Check existence. | PHP |
[x*x for x in arr if x > 7] | [x*x for x in arr if x > 7] | Correct list comprehension. | Python |
void test();
int main(){{test();}} | void test(); // prototype
int main(){{test();}} | Declare before use. | C++ |
for i=1,86 do print(i) end | for i=1,86 do print(i) end | Correct. | Lua |
if ($val = 84) | if ($val == 84) | Use ==. | Perl |
<div><p>data</div></p> | <div><p>data</p></div> | Nest properly. | HTML |
let y = 52; y += 1; | let mut y = 52; y += 1; | Need mut to modify. | Rust |
object Product {{ def main(args: Array[String]) = println("hello") }} | object Product {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
try {{ throw 'output'; }} catch(e) {{}} | try {{ throw new Error('output'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
<note name='output'/> | <note name="output"/> | Double quotes. | XML |
x > 91 & y < 70 | x > 91 and y < 70 | Use 'and' not '&'. | Python |
{{"title":"data",}} | {{"title":"data"}} | Remove trailing comma. | JSON |
if count = 29 | if count == 29 | Use ==. | MATLAB |
if temp = 95 | if temp == 95 | Use ==. | Ruby |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
var x = 85; | var x = 85; | Correct. | Dart |
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
if (data = 54) | if (data == 54) | Use ==. | R |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
#main {{ color: green; }} | #main {{ color: green; }} | Correct. | CSS |
x := 100 | x := 100 | Correct. | Go |
{{'status':'message'}} | {{"status":"message"}} | Use double quotes. | JSON |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
let str = String::from("world"); let ref=&str; str.push_str("!"); | let mut str = String::from("world"); let ref=&str; println!("{{}}", ref); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
let vec=vec![70,53,28]; let head=&vec[0]; vec.push(16); | let mut vec=vec![70,53,28]; let head=vec[0]; vec.push(16); | Copy instead of reference. | Rust |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
echo result world | echo 'result world' | Quote to prevent splitting. | Shell |
int list[86]; list[86]=5; | int list[86]; if(86<86){{}} else list[86]=5; | Bounds check. | C++ |
// comment | /* comment */ | Use /* */. | CSS |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
'output' + 61 | 'output' + str(61) | Can't add int to string. | Python |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
SELECT * FROM orders WHRE name=3; | SELECT * FROM orders WHERE name=3; | Fix WHERE. | SQL |
disp('test') | disp('test') | Correct. | MATLAB |
void main() {{ print('info') }} | void main() {{ print('info'); }} | Add semicolon. | Dart |
Write-Host 'value' | Write-Host 'value' | Correct. | PowerShell |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
values[55] | if (length(values) >= 55) values[55] | Check length. | R |
<user><desc>result</desc><name>84</name></user | <user><desc>result</desc><name>84</name></user> | Add closing >. | XML |
<br></br> | <br> | Self-closing. | HTML |
function test(data)
print(data)
end | function test(data)
print(data)
end | Correct. | Lua |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
foo == '38' | foo === 38 | Use strict equality. | JavaScript |
items(14) | if length(items) >= 14, items(14), end | Check length. | MATLAB |
age: hello
id: world, | age: hello
id: world | Remove comma. | YAML |
$item = 23; if ($item = 23) {{}} | $item = 23; if ($item == 23) {{}} | Use ==. | PHP |
switch(z){{ case 61: break; }} | switch(z){{ case 61: break; default: break; }} | Add default case. | Java |
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