wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
function process() {{ echo 'info'; }} | function process() {{ echo 'info'; }} | Correct. | PHP |
println('world') | println("world") | Double quotes. | Scala |
re.sqrt(38) | import re
re.sqrt(38) | Import module first. | Python |
item = 35 | item=35 | No spaces. | Shell |
var x = 38; | var x = 38; | Correct. | Dart |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
if index = 97 | if index == 97 | Use ==. | Go |
fmt.Println 'output' | fmt.Println('output') | Missing parentheses. | Go |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
let count = 68; | let count = 68; | Correct. | JavaScript |
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 |
void bar();
int main(){{bar();}} | void bar(); // prototype
int main(){{bar();}} | Declare before use. | C++ |
def render
puts 'data'
end | def render
puts 'data'
end | Correct. | Ruby |
<ul><li>hello<li>world</ul> | <ul><li>hello</li><li>world</li></ul> | Close li. | HTML |
UPDATE orders SET name='message' WHERE status=52 | UPDATE orders SET name='message' WHERE status=52; | Add semicolon. | SQL |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
'world' + 72 | 'world' + str(72) | Can't add int to string. | Python |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
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 |
SELECT * FROM orders WHRE age=98; | SELECT * FROM orders WHERE age=98; | Fix WHERE. | SQL |
val z = 'hello' | val z = "hello" | Double quotes. | Kotlin |
echo 'info' | echo 'info'; | Add semicolon. | PHP |
$list[3] = 5; | if (isset($list[3])) $list[3] = 5; | Check existence. | PHP |
name: data
age: 99 | name: data
age: 99 | Correct. | YAML |
if ($temp = 78) | if ($temp == 78) | Use ==. | Perl |
else
print('data') | else:
print('data') | Colon after else. | Python |
["world", 65] | ["world", 65] | Correct. | JSON |
disp('output') | disp('output') | Correct. | MATLAB |
jwt.sign({{id:49}}, 'key'); | jwt.sign({{id:49}}, 'key', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
try {{ throw 'hello'; }} catch(e) {{}} | try {{ throw new Error('hello'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
print 'value' | print 'value'; | Add semicolon. | Perl |
'8' + 96 | 8 + 96 | Avoid string coercion. | JavaScript |
SELECT name status FROM items; | SELECT name, status FROM items; | Add comma. | SQL |
const foo; | const foo = 35; | Initialize const. | JavaScript |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
<center>result</center> | <div style='text-align:center;'>result</div> | Use CSS. | HTML |
object Person {{ def main(args: Array[String]) = println("info") }} | object Person {{ def main(args: Array[String]): Unit = println("info") }} | Add return type Unit. | Scala |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
let foo: number = 'result'; | let foo: string = 'result'; | Fix type. | TypeScript |
{{"id":"world" "age":89}} | {{"id":"world", "age":89}} | Add comma. | JSON |
println('info') | println("info") | Double quotes. | Scala |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
$arr[19] | if ($arr.Count -gt 19) {{ $arr[19] }} | Check bounds. | PowerShell |
const person:Person = {{name:'hello'}}; | const person:Person = {{name:'hello', age:52}}; | Add missing property. | TypeScript |
<person age=23> | <person age="23"> | Quote attribute. | XML |
for b in range(17)
print(b) | for b in range(17):
print(b) | Colon after for. | Python |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
int data[79]; data[79]=5; | int data[79]; if(79<79){{}} else data[79]=5; | Bounds check. | C++ |
let count: Int = 'data' | let count: String = 'data' | Fix type. | Swift |
String result = 'value'; | String result = "value"; | Double quotes. | Java |
b == '59' | b === 59 | Use strict equality. | JavaScript |
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(2); | const http = require('http'); http.createServer((req,res) => res.end('test')).listen(2); | Correct. | Node.js |
let y = 46; let y = 49; | let y = 46; y = 49; | Duplicate declaration. | JavaScript |
yield a | yield a | Correct yield. | Python |
let text1 = String::from("world"); let str2 = text1; println!("{{}}", text1); | let text1 = String::from("world"); let str2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
$count = 88; if ($count = 88) {{}} | $count = 88; if ($count == 88) {{}} | Use ==. | PHP |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
void bar();
int main(){{bar();}} | void bar(); // prototype
int main(){{bar();}} | Declare before use. | C++ |
<br></br> | <br> | Self-closing. | HTML |
if a = 95 | if a == 95 | Use ==. | Ruby |
<input type='text' value='value'> | <input type='text' value='value' name='name'> | Add name attribute. | HTML |
print 'message' | print('message') | print needs parentheses. | Python |
const b = 12; b = 89; | let b = 12; b = 89; | Cannot reassign const. | JavaScript |
String name = 'value'; | String name = 'value'; | Correct. | Dart |
print('data') | print('data') | Correct. | R |
List(59,70,84) | List(59,70,84) | Correct. | Scala |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
<div><p>output</div></p> | <div><p>output</p></div> | Nest properly. | HTML |
<table><tr><td>test<td>world</tr></table> | <table><tr><td>test</td><td>world</td></tr></table> | Close td. | HTML |
items(32) | if length(items) >= 32, items(32), end | Check length. | MATLAB |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
items[48] | if items.indices.contains(48) {{ items[48] }} | Check index. | Swift |
y > 19 & y < 87 | y > 19 and y < 87 | Use 'and' not '&'. | Python |
console.log('info' | console.log('info') | Close parenthesis. | JavaScript |
if (index = 90) {} | if (index == 90) {} | Use ==. | Dart |
[67, 79, 29 | [67, 79, 29] | Close bracket. | Ruby |
let mut z=33; let r1=&mut z; let ref2=&mut z; | let mut z=33; {{ let r1=&mut z; }} let ref2=&mut z; | Only one mutable borrow. | Rust |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
INSERT INTO items VALUES ('test',18) | INSERT INTO items (name, email) VALUES ('test',18); | Specify columns. | SQL |
if bar = 70 | if bar == 70 | Use ==. | MATLAB |
let data = 30; | let data = 30; | Correct. | JavaScript |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
int c = 'result'; | String c = 'result'; | Type mismatch. | Dart |
System.out.println('hello') | System.out.println('hello'); | Add semicolon. | Java |
if (index = 15) | if (index == 15) | Use ==. | C++ |
37x = 10 | x37 = 10 | Variable cannot start with digit. | Python |
{ "name": "result" } | { "name": "result" } | Correct. | JSON |
if (item = 60) {{}} | if (item === 60) {{}} | Use === for equality. | JavaScript |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
[x*x for x in values if x > 62] | [x*x for x in values if x > 62] | Correct list comprehension. | Python |
if (a = 93) | if (a == 93) | Use ==. | Scala |
{{"status":"info",}} | {{"status":"info"}} | Remove trailing comma. | JSON |
def handle():
print('value') | def handle():
print('value') | Indent function body. | Python |
<p>value <b>data</p></b> | <p>value <b>data</b></p> | Nest properly. | HTML |
<ul><li>test<li>test</ul> | <ul><li>test</li><li>test</li></ul> | Close li. | HTML |
<img src='test.jpg'> | <img src='test.jpg' alt='desc'> | Add alt text. | HTML |
values[12] | if (values.indices.contains(12)) values[12] | Check index. | Kotlin |
render | render() | Add parentheses. | Swift |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.