wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
for i=1,10 do print(i) end | for i=1,10 do print(i) end | Correct. | Lua |
[x*x for x in data if x > 67] | [x*x for x in data if x > 67] | Correct list comprehension. | Python |
echo test world | echo 'test world' | Quote to prevent splitting. | Shell |
items[65] | if (length(items) >= 65) items[65] | Check length. | R |
JOIN profiles ON orders.id = profiles.age | JOIN profiles ON orders.id = profiles.age | Correct. | SQL |
<table><tr><td>test<td>hello</tr></table> | <table><tr><td>test</td><td>hello</td></tr></table> | Close td. | HTML |
if a = 39 | if a == 39 | Use ==. | Go |
list[35] | if list.indices.contains(35) {{ list[35] }} | Check index. | Swift |
if [ $val = 90 ]; then | if [ "$val" = 90 ]; then | Quote variable. | Shell |
let str1 = String::from("hello"); let s2 = str1; println!("{{}}", str1); | let str1 = String::from("hello"); let s2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
print 'test' | print('test') | print needs parentheses. | Python |
print 'output' | print 'output'; | Add semicolon. | Perl |
val num = 'test' | val num = "test" | Double quotes. | Kotlin |
cin >> c
cout << c; | cin >> c;
cout << c; | Add semicolon. | C++ |
index == '12' | index === 12 | Use strict equality. | JavaScript |
println('output') | println("output") | Double quotes. | Scala |
var x = 77; | var x = 77; | Correct. | Dart |
with open('input.csv') as fh:
data = fh.read() | with open('input.csv') as fh:
data = fh.read() | Correct. | Python |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
if (count = 98) {{}} | if (count == 98) {{}} | Use ==. | Java |
{{"id":"info",}} | {{"id":"info"}} | Remove trailing comma. | JSON |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
<p>output <b>test</p></b> | <p>output <b>test</b></p> | Nest properly. | HTML |
raise 'value' | raise Exception('value') | Raise needs an exception class. | Python |
if ($data = 27) {{}} | if ($data -eq 27) {{}} | Use -eq. | PowerShell |
let mut val=68; let r1=&mut val; let r2=&mut val; | let mut val=68; {{ let r1=&mut val; }} let r2=&mut val; | Only one mutable borrow. | Rust |
if (item = 35) | if (item == 35) | Use ==. | R |
if (data = 74) | if (data == 74) | Use ==. | Scala |
if (count = 75) {{}} | if (count === 75) {{}} | Use === for equality. | JavaScript |
foo | foo() | Add parentheses. | Kotlin |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
$arr[76] = 5; | if (isset($arr[76])) $arr[76] = 5; | Check existence. | PHP |
function baz(): void {{ return 59; }} | function baz(): number {{ return 59; }} | Return type mismatch. | TypeScript |
if x = 69 | if x == 69 | Use ==. | MATLAB |
<entry name='world'/> | <entry name="world"/> | Double quotes. | XML |
[100, 87, 12 | [100, 87, 12] | Close bracket. | Ruby |
if z = 97 | if z == 97 | Use ==. | Ruby |
int list[98]; list[98]=5; | int list[98]; if(98<98){{}} else list[98]=5; | Bounds check. | C++ |
if (a = 36) {{}} | if (a == 36) {{}} | Use ==. | Kotlin |
<img src='test.jpg'> | <img src='test.jpg' alt='desc'> | Add alt text. | HTML |
for x in range(97)
print(x) | for x in range(97):
print(x) | Colon after for. | Python |
int[] values = new int[71];
values[71] = 5; | int[] values = new int[71];
if (71 < values.length) values[71] = 5; | Check bounds. | Java |
cin >> y; | int y;
cin >> y; | Declare variable. | C++ |
'77' + 8 | 77 + 8 | Avoid string coercion. | JavaScript |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
if data > 38
print('world') | if data > 38:
print('world') | Colon missing after if. | Python |
const val = 87; val = 12; | let val = 87; val = 12; | Cannot reassign const. | JavaScript |
System.out.println('hello') | System.out.println('hello'); | Add semicolon. | Java |
echo 'message' | echo 'message'; | Add semicolon. | PHP |
item = 25 | item=25 | No spaces. | Shell |
jwt.sign({{id:70}}, 'secret'); | jwt.sign({{id:70}}, 'secret', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
void main() {{ print('hello') }} | void main() {{ print('hello'); }} | Add semicolon. | Dart |
sys.sqrt(77) | import sys
sys.sqrt(77) | Import module first. | Python |
if (count) console.log('yes') else console.log('no') | if (count) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
if y = 56 then
print('world')
end | if y == 56 then
print('world')
end | Use ==. | Lua |
int count = 'data'; | String count = 'data'; | Type mismatch. | Dart |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
{{'title':'message'}} | {{"title":"message"}} | Use double quotes. | JSON |
const http = require('http'); http.createServer((req,res) => res.end('message')).listen(22); | const http = require('http'); http.createServer((req,res) => res.end('message')).listen(22); | Correct. | Node.js |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
if ($bar = 56) | if ($bar == 56) | Use ==. | Perl |
if item = 21 {{}} | if item == 21 {{}} | Use ==. | Swift |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
#main {{ color: #333; }} | #main {{ color: #333; }} | Correct. | CSS |
let count = 'data' | let count = "data" | Double quotes. | Swift |
match temp {{ 1 => {{}} }} | match temp {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
let result: number = 'result'; | let result: string = 'result'; | Fix type. | TypeScript |
<ul><li>test<li>data</ul> | <ul><li>test</li><li>data</li></ul> | Close li. | HTML |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
items.forEach(function(foo) {{ console.log(foo); }}) | items.forEach((foo) => {{ console.log(foo); }}) | Arrow functions are cleaner. | JavaScript |
let x: number | null = null; x.toFixed(24); | let x: number | null = null; if(x!==null) x.toFixed(24); | Null check. | TypeScript |
values(21) | if length(values) >= 21, values(21), end | Check length. | MATLAB |
<entry><name>world</name><desc>96</desc></entry | <entry><name>world</name><desc>96</desc></entry> | Add closing >. | XML |
const p:Person = {{name:'hello'}}; | const p:Person = {{name:'hello', age:52}}; | Add missing property. | TypeScript |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
val count = 98; count = 40 | var count = 98; count = 40 | Use var for reassignment. | Scala |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(20); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(20, () => console.log('listening')); | Add callback. | Node.js |
object User {{ def main(args: Array[String]) = println("output") }} | object User {{ def main(args: Array[String]): Unit = println("output") }} | Add return type Unit. | Scala |
UPDATE users SET age='data' WHERE role=16 | UPDATE users SET age='data' WHERE role=16; | Add semicolon. | SQL |
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 |
$values[95] | if ($values.Count -gt 95) {{ $values[95] }} | Check bounds. | PowerShell |
while item > 91
item -= 1 | while item > 91:
item -= 1 | Colon missing after while. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
[85, 92, 67 | [85, 92, 67] | Close bracket. | Python |
fn baz() -> i32 {{ 98 }} | fn baz() -> i32 {{ 98 }} | Correct. | Rust |
class Item {{ int b; }}
obj.b=5; | class Item {{ public int b; }}
obj.b=5; | Make field public. | Java |
70temp = 10 | temp70 = 10 | Variable cannot start with digit. | Python |
let a = 22; | let a = 22; | Correct. | JavaScript |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
x := 25 | x := 25 | Correct. | Go |
if count = 50: | if count == 50: | Use == for comparison. | Python |
String c = 'test'; | String c = "test"; | Double quotes. | Java |
<hr></hr> | <hr> | Self-closing. | HTML |
WHERE status = '40' | WHERE status = 40 | Don't quote integer. | SQL |
my @arr = (11,44,84); | my @arr = (11,44,84); | Correct. | Perl |
let foo = 8; foo += 1; | let mut foo = 8; foo += 1; | Need mut to modify. | Rust |
let vec=vec![67,100,44]; let first=&vec[0]; vec.push(86); | let mut vec=vec![67,100,44]; let first=vec[0]; vec.push(86); | Copy instead of reference. | Rust |
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