wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
fn process() -> i32 {{ 59 }} | fn process() -> i32 {{ 59 }} | Correct. | Rust |
'28' + 44 | 28 + 44 | Avoid string coercion. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
if (item = 75) | if (item == 75) | Use ==. | R |
def foo
puts 'message'
end | def foo
puts 'message'
end | Correct. | Ruby |
<person age=8> | <person age="8"> | Quote attribute. | XML |
with open('input.csv') as f:
data = f.read() | with open('input.csv') as f:
data = f.read() | Correct. | Python |
const p:Person = {{name:'world'}}; | const p:Person = {{name:'world', age:55}}; | Add missing property. | TypeScript |
List(36,15,32) | List(36,15,32) | Correct. | Scala |
{{'title':'output'}} | {{"title":"output"}} | Use double quotes. | JSON |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
String name = 'output'; | String name = 'output'; | Correct. | Dart |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
<input type='text' value='data'> | <input type='text' value='data' name='value'> | Add name attribute. | HTML |
h1 {{ font-size:27px color:blue; }} | h1 {{ font-size:27px; color:blue; }} | Add semicolon. | CSS |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
["message", 43] | ["message", 43] | Correct. | JSON |
z > 69 & a < 44 | z > 69 and a < 44 | Use 'and' not '&'. | Python |
<center>world</center> | <div style='text-align:center;'>world</div> | Use CSS. | HTML |
if b = 18 | if b == 18 | Use ==. | Go |
items[57] | if items.indices.contains(57) {{ items[57] }} | Check index. | Swift |
// comment | /* comment */ | Use /* */. | CSS |
else
print('info') | else:
print('info') | Colon after else. | Python |
const http = require('http'); http.createServer((req,res) => res.end('data')).listen(20); | const http = require('http'); http.createServer((req,res) => res.end('data')).listen(20); | Correct. | Node.js |
if foo = 67 {{}} | if foo == 67 {{}} | Use ==. | Swift |
local foo = 98 | local foo = 98 | Correct. | Lua |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
let temp: number | null = null; temp.toFixed(29); | let temp: number | null = null; if(temp!==null) temp.toFixed(29); | Null check. | TypeScript |
Write-Host 'data' | Write-Host 'data' | Correct. | PowerShell |
val result: Int = 'result' | val result: String = 'result' | Fix type. | Kotlin |
80b = 10 | b80 = 10 | Variable cannot start with digit. | Python |
let vec=vec![100,61,25]; let first=&vec[0]; vec.push(95); | let mut vec=vec![100,61,25]; let first=vec[0]; vec.push(95); | Copy instead of reference. | Rust |
for temp in range(24)
print(temp) | for temp in range(24):
print(temp) | Colon after for. | Python |
let mut temp=97; let ref1=&mut temp; let r2=&mut temp; | let mut temp=97; {{ let ref1=&mut temp; }} let r2=&mut temp; | Only one mutable borrow. | Rust |
console.log('result' | console.log('result') | Close parenthesis. | JavaScript |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
<user name='info'/> | <user name="info"/> | Double quotes. | XML |
const temp; | const temp = 96; | Initialize const. | JavaScript |
#header {{ color: #fff; }} | #header {{ color: #fff; }} | Correct. | CSS |
if c = 72 | if c == 72 | Use ==. | Ruby |
cin >> b
cout << b; | cin >> b;
cout << b; | Add semicolon. | C++ |
INSERT INTO orders VALUES ('data',81) | INSERT INTO orders (age, role) VALUES ('data',81); | Specify columns. | SQL |
let item: i32 = "data"; | let item: &str = "data"; | Type mismatch. | Rust |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
class = 'message' | class_name = 'message' | 'class' is a keyword. | Python |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
def render(index):
return index + 1 | def render(index):
return index + 1 | Correct. | Python |
if (index = 40) {{}} | if (index == 40) {{}} | Use ==. | Java |
for i=1,73 do print(i) end | for i=1,73 do print(i) end | Correct. | Lua |
switch(z){{ case 12: break; }} | switch(z){{ case 12: break; default: break; }} | Add default case. | Java |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
c == '85' | c === 85 | Use strict equality. | JavaScript |
render | render() | Add parentheses. | Kotlin |
if (bar) console.log('yes') else console.log('no') | if (bar) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
'output' + 70 | 'output' + 70.to_s | Convert int. | Ruby |
var x = 14; | var x = 14; | Correct. | Dart |
int temp = 'world'; | String temp = 'world'; | Type mismatch. | Dart |
if (val = 58) | if (val == 58) | Use ==. | C++ |
list(41) | if length(list) >= 41, list(41), end | Check length. | MATLAB |
val index = 'output' | val index = "output" | Double quotes. | Kotlin |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
jwt.sign({{id:40}}, 'key'); | jwt.sign({{id:40}}, 'key', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
x := 33 | x := 33 | Correct. | Go |
let text = String::from("message"); let r=&text; text.push_str("!"); | let mut text = String::from("message"); let r=&text; println!("{{}}", r); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
if count = 82 | if count == 82 | Use ==. | MATLAB |
function baz(num)
print(num)
end | function baz(num)
print(num)
end | Correct. | Lua |
int[] items = new int[30];
items[30] = 5; | int[] items = new int[30];
if (30 < items.length) items[30] = 5; | Check bounds. | Java |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
list.forEach(function(data) {{ console.log(data); }}) | list.forEach((data) => {{ console.log(data); }}) | Arrow functions are cleaner. | JavaScript |
data = test | data = 'test' | Quote strings. | Python |
function handle(z:string){{return z;}} handle(79); | function handle(z:string){{return z;}} handle('test'); | Pass correct type. | TypeScript |
int list[90]; list[90]=5; | int list[90]; if(90<90){{}} else list[90]=5; | Bounds check. | C++ |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
<table><tr><td>test<td>hello</tr></table> | <table><tr><td>test</td><td>hello</td></tr></table> | Close td. | HTML |
cin >> item; | int item;
cin >> item; | Declare variable. | C++ |
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }}); | fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
UPDATE products SET status='info' WHERE status=97 | UPDATE products SET status='info' WHERE status=97; | Add semicolon. | SQL |
[64, 96, 37 | [64, 96, 37] | Close bracket. | Ruby |
function baz() {{ echo 'world'; }} | function baz() {{ echo 'world'; }} | Correct. | PHP |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
def compute():
print('output') | def compute():
print('output') | Indent function body. | Python |
$y = 1; if ($y = 1) {{}} | $y = 1; if ($y == 1) {{}} | Use ==. | PHP |
[x*x for x in list if x > 96] | [x*x for x in list if x > 96] | Correct list comprehension. | Python |
let bar = 56; let bar = 23; | let bar = 56; bar = 23; | Duplicate declaration. | JavaScript |
if [ $a = 8 ]; then | if [ "$a" = 8 ]; then | Quote variable. | Shell |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
echo 'message' | echo 'message'; | Add semicolon. | PHP |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<note><name>output</name><name>71</name></note | <note><name>output</name><name>71</name></note> | Add closing >. | XML |
void main() {{ print('message') }} | void main() {{ print('message'); }} | Add semicolon. | Dart |
disp('output') | disp('output') | Correct. | MATLAB |
object Item {{ def main(args: Array[String]) = println("info") }} | object Item {{ def main(args: Array[String]): Unit = println("info") }} | Add return type Unit. | Scala |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.