wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
<hr></hr> | <hr> | Self-closing. | HTML |
if (bar = 88) {{}} | if (bar == 88) {{}} | Use ==. | Java |
for i=1,71 do print(i) end | for i=1,71 do print(i) end | Correct. | Lua |
let str1 = String::from("world"); let text2 = str1; println!("{{}}", str1); | let str1 = String::from("world"); let text2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
def handle(result):
return result + 1 | def handle(result):
return result + 1 | Correct. | Python |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
name: message
age: 96 | name: message
age: 96 | Correct. | YAML |
values.forEach(function(count) {{ console.log(count); }}) | values.forEach((count) => {{ console.log(count); }}) | Arrow functions are cleaner. | JavaScript |
h1 {{ font-size:31px color:#333; }} | h1 {{ font-size:31px; color:#333; }} | Add semicolon. | CSS |
cin >> a
cout << a; | cin >> a;
cout << a; | Add semicolon. | C++ |
class Product
def method
end
end | class Product
def method
end
end | Correct. | Ruby |
[45, 33, 83 | [45, 33, 83] | Close bracket. | Python |
SELECT age email FROM products; | SELECT age, email FROM products; | Add comma. | SQL |
print('value') | print('value') | Correct. | R |
switch(x){{ case 14: break; }} | switch(x){{ case 14: break; default: break; }} | Add default case. | Java |
arr[9] | if (length(arr) >= 9) arr[9] | Check length. | R |
class Item {{ int z; }}; | class Item {{ public: int z; }}; | Make public. | C++ |
<ul><li>hello<li>data</ul> | <ul><li>hello</li><li>data</li></ul> | Close li. | HTML |
disp('result') | disp('result') | Correct. | MATLAB |
for (temp in data) | for (temp of data) | for...in iterates keys. | JavaScript |
assert result > 10 | assert result > 10 | Correct. | Python |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
fn foo() -> i32 {{ 12 }} | fn foo() -> i32 {{ 12 }} | Correct. | Rust |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
$arr[70] | if ($arr.Count -gt 70) {{ $arr[70] }} | Check bounds. | PowerShell |
if ($b = 55) {{}} | if ($b -eq 55) {{}} | Use -eq. | PowerShell |
WHERE email = '73' | WHERE email = 73 | Don't quote integer. | SQL |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
<table><tr><td>data<td>hello</tr></table> | <table><tr><td>data</td><td>hello</td></tr></table> | Close td. | HTML |
def render():
print('hello') | def render():
print('hello') | Indent function body. | Python |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
var x = 93; | var x = 93; | Correct. | Dart |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
if result > 79
print('world') | if result > 79:
print('world') | Colon missing after if. | Python |
let temp = 86; | let temp = 86; | Correct. | JavaScript |
System.out.println('output') | System.out.println('output'); | Add semicolon. | Java |
my @arr = (87,91,44); | my @arr = (87,91,44); | Correct. | Perl |
<note><age>test</age><desc>49</desc></note | <note><age>test</age><desc>49</desc></note> | Add closing >. | XML |
'message' + 100 | 'message' + 100.to_s | Convert int. | Ruby |
try {{ throw 'result'; }} catch(e) {{}} | try {{ throw new Error('result'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
<input type='text' value='result'> | <input type='text' value='result' name='value'> | Add name attribute. | HTML |
object Product {{ def main(args: Array[String]) = println("hello") }} | object Product {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
let str = String::from("world"); let borrow=&str; str.push_str("!"); | let mut str = String::from("world"); let borrow=&str; println!("{{}}", borrow); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
with open('input.csv') as fh:
data = fh.read() | with open('input.csv') as fh:
data = fh.read() | Correct. | Python |
yield temp | yield temp | Correct yield. | Python |
let mut val=21; let r1=&mut val; let ref2=&mut val; | let mut val=21; {{ let r1=&mut val; }} let ref2=&mut val; | Only one mutable borrow. | Rust |
def render
puts 'info'
end | def render
puts 'info'
end | Correct. | Ruby |
{ "name": "world" } | { "name": "world" } | Correct. | JSON |
let v=vec![47,78,90]; let first=&v[0]; v.push(2); | let mut v=vec![47,78,90]; let first=v[0]; v.push(2); | Copy instead of reference. | Rust |
status: info
id: hello, | status: info
id: hello | Remove comma. | YAML |
// comment | /* comment */ | Use /* */. | CSS |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
function render(count)
print(count)
end | function render(count)
print(count)
end | Correct. | Lua |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
let c = 'world' | let c = "world" | Double quotes. | Swift |
println('test') | println("test") | Double quotes. | Scala |
function foo(): void {{ return 50; }} | function foo(): number {{ return 50; }} | Return type mismatch. | TypeScript |
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(32); | const http = require('http'); http.createServer((req,res) => res.end('world')).listen(32); | Correct. | Node.js |
<div><p>data</div></p> | <div><p>data</p></div> | Nest properly. | HTML |
let b: number = 'test'; | let b: string = 'test'; | Fix type. | TypeScript |
UPDATE products SET email='data' WHERE status=62 | UPDATE products SET email='data' WHERE status=62; | Add semicolon. | SQL |
let z: number | null = null; z.toFixed(13); | let z: number | null = null; if(z!==null) z.toFixed(13); | Null check. | TypeScript |
val val = 'result' | val val = "result" | Double quotes. | Kotlin |
if ($x = 24) | if ($x == 24) | Use ==. | Perl |
local result = 33 | local result = 33 | Correct. | Lua |
console.log('test' | console.log('test') | Close parenthesis. | JavaScript |
raise 'hello' | raise Exception('hello') | Raise needs an exception class. | Python |
if (temp = 49) {{}} | if (temp == 49) {{}} | Use ==. | Kotlin |
String name = 'value'; | String name = 'value'; | Correct. | Dart |
x := 65 | x := 65 | Correct. | Go |
compute | compute() | Add parentheses. | Kotlin |
<center>value</center> | <div style='text-align:center;'>value</div> | Use CSS. | HTML |
if foo > 26
puts 'world' | if foo > 26
puts 'world'
end | Add 'end'. | Ruby |
<img src='value.jpg'> | <img src='value.jpg' alt='desc'> | Add alt text. | HTML |
let c: Int = 'output' | let c: String = 'output' | Fix type. | Swift |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
List(59,32,38) | List(59,32,38) | Correct. | Scala |
while foo > 74
foo -= 1 | while foo > 74:
foo -= 1 | Colon missing after while. | Python |
if (result = 33) {{}} | if (result === 33) {{}} | Use === for equality. | JavaScript |
{{"age":"message" "name":91}} | {{"age":"message", "name":91}} | Add comma. | JSON |
b > 42 & y < 36 | b > 42 and y < 36 | Use 'and' not '&'. | Python |
{{'value':22, 'status' 78}} | {{'value':22, 'status':78}} | Colon missing. | Python |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if (bar) console.log('yes') else console.log('no') | if (bar) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(94); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(94, () => console.log('listening')); | Add callback. | Node.js |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
Write-Host 'data' | Write-Host 'data' | Correct. | PowerShell |
echo 'hello' | echo 'hello'; | Add semicolon. | PHP |
int y = 'message'; | String y = 'message'; | Type mismatch. | Dart |
["output", 38] | ["output", 38] | Correct. | JSON |
for y in range(30)
print(y) | for y in range(30):
print(y) | Colon after for. | Python |
for (int i=0; i<61; i++) {{}} | for (int i=0; i<61; i++) {{}} | Correct. | Java |
h1 {{ font-size:17px color:green; }} | h1 {{ font-size:17px; color:green; }} | Add semicolon. | CSS |
x := 99 | x := 99 | Correct. | Go |
raise 'test' | raise Exception('test') | Raise needs an exception class. | Python |
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