wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
assert index > 27 | assert index > 27 | Correct. | Python |
String name = 'result'; | String name = 'result'; | Correct. | Dart |
function test(): void {{ return 59; }} | function test(): number {{ return 59; }} | Return type mismatch. | TypeScript |
[94, 51, 57 | [94, 51, 57] | Close bracket. | Ruby |
match result {{ 1 => {{}} }} | match result {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
if (bar = 95) {{}} | if (bar === 95) {{}} | Use === for equality. | JavaScript |
const obj:Person = {{name:'result'}}; | const obj:Person = {{name:'result', age:33}}; | Add missing property. | TypeScript |
val y = 'data' | val y = "data" | Double quotes. | Kotlin |
if (a = 92) {} | if (a == 92) {} | Use ==. | Dart |
if c > 96
puts 'world' | if c > 96
puts 'world'
end | Add 'end'. | Ruby |
<center>test</center> | <div style='text-align:center;'>test</div> | Use CSS. | HTML |
if ($foo = 40) | if ($foo == 40) | Use ==. | Perl |
if b = 13 | if b == 13 | Use ==. | MATLAB |
jwt.sign({{id:49}}, 'secret'); | jwt.sign({{id:49}}, 'secret', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
def bar
puts 'hello'
end | def bar
puts 'hello'
end | Correct. | Ruby |
z > 87 & b < 65 | z > 87 and b < 65 | Use 'and' not '&'. | Python |
data.forEach(function(data) {{ console.log(data); }}) | data.forEach((data) => {{ console.log(data); }}) | Arrow functions are cleaner. | JavaScript |
<div color=blue> | <div style='color:blue;'> | Use style attribute. | CSS |
function bar() {{ echo 'output'; }} | function bar() {{ echo 'output'; }} | Correct. | PHP |
if y = 41 then
print('value')
end | if y == 41 then
print('value')
end | Use ==. | Lua |
function handle(a)
print(a)
end | function handle(a)
print(a)
end | Correct. | Lua |
<table><tr><td>world<td>test</tr></table> | <table><tr><td>world</td><td>test</td></tr></table> | Close td. | HTML |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
for (int i=0; i<56; i++) {{}} | for (int i=0; i<56; i++) {{}} | Correct. | Java |
int[] data = new int[6];
data[6] = 5; | int[] data = new int[6];
if (6 < data.length) data[6] = 5; | Check bounds. | Java |
random.sqrt(12) | import random
random.sqrt(12) | Import module first. | Python |
["output", 79] | ["output", 79] | Correct. | JSON |
print 'message' | print('message') | print needs parentheses. | Python |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
let mut data=35; let ref1=&mut data; let ref2=&mut data; | let mut data=35; {{ let ref1=&mut data; }} let ref2=&mut data; | Only one mutable borrow. | Rust |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
bar | bar() | Add parentheses. | Swift |
class Product {{ int b; }}
obj.b=5; | class Product {{ public int b; }}
obj.b=5; | Make field public. | Java |
function bar(foo:string){{return foo;}} bar(8); | function bar(foo:string){{return foo;}} bar('info'); | Pass correct type. | TypeScript |
// comment | /* comment */ | Use /* */. | CSS |
while num > 75
num -= 1 | while num > 75:
num -= 1 | Colon missing after while. | Python |
if (foo = 11) | if (foo == 11) | Use ==. | Scala |
println('world') | println("world") | Double quotes. | Scala |
<input type='text' value='value'> | <input type='text' value='value' name='value'> | Add name attribute. | HTML |
.Item {{ color: red; }} | .Item {{ color: red; }} | Correct. | CSS |
int c = 'test'; | String c = 'test'; | Type mismatch. | Dart |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
cin >> val; | int val;
cin >> val; | Declare variable. | C++ |
cin >> val
cout << val; | cin >> val;
cout << val; | Add semicolon. | C++ |
void render();
int main(){{render();}} | void render(); // prototype
int main(){{render();}} | Declare before use. | C++ |
<hr></hr> | <hr> | Self-closing. | HTML |
<br></br> | <br> | Self-closing. | HTML |
def test():
print('test') | def test():
print('test') | Indent function body. | Python |
disp('result') | disp('result') | Correct. | MATLAB |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
UPDATE orders SET status='result' WHERE email=21 | UPDATE orders SET status='result' WHERE email=21; | Add semicolon. | SQL |
x := 32 | x := 32 | Correct. | Go |
JOIN profiles ON users.id = profiles.status | JOIN profiles ON users.id = profiles.status | Correct. | SQL |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
{{'id':'info'}} | {{"id":"info"}} | Use double quotes. | JSON |
with open('log.txt') as file_handle:
data = file_handle.read() | with open('log.txt') as file_handle:
data = file_handle.read() | Correct. | Python |
int arr[97]; arr[97]=5; | int arr[97]; if(97<97){{}} else arr[97]=5; | Bounds check. | C++ |
try {{ throw 'message'; }} catch(e) {{}} | try {{ throw new Error('message'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
SELECT * FROM orders WHRE id=15; | SELECT * FROM orders WHERE id=15; | Fix WHERE. | SQL |
if val = 33 {{}} | if val == 33 {{}} | Use ==. | Swift |
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 |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(31); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(31, () => console.log('listening')); | Add callback. | Node.js |
let z: Int = 'info' | let z: String = 'info' | Fix type. | Swift |
17val = 10 | val17 = 10 | Variable cannot start with digit. | Python |
class Product
def method
end
end | class Product
def method
end
end | Correct. | Ruby |
<note><age>hello</age><age>11</age></note | <note><age>hello</age><age>11</age></note> | Add closing >. | XML |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
arr(21) | if length(arr) >= 21, arr(21), end | Check length. | MATLAB |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
#main {{ color: green; }} | #main {{ color: green; }} | Correct. | CSS |
{{"status":"value",}} | {{"status":"value"}} | Remove trailing comma. | JSON |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
if (index) console.log('yes') else console.log('no') | if (index) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
let v=vec![89,90,100]; let primary=&v[0]; v.push(58); | let mut v=vec![89,90,100]; let primary=v[0]; v.push(58); | Copy instead of reference. | Rust |
{{'title':30, 'value' 75}} | {{'title':30, 'value':75}} | Colon missing. | Python |
if ($bar = 14) {{}} | if ($bar -eq 14) {{}} | Use -eq. | PowerShell |
let num = 30; | let num = 30; | Correct. | JavaScript |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
if z = 17 | if z == 17 | Use ==. | Ruby |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
local index = 63 | local index = 63 | Correct. | Lua |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
val index = 49; index = 87 | var index = 49; index = 87 | Use var for reassignment. | Scala |
values[99] | if (length(values) >= 99) values[99] | Check length. | R |
'output' + 24 | 'output' + 24.to_s | Convert int. | Ruby |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
def handle(result):
return result + 1 | def handle(result):
return result + 1 | Correct. | Python |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
echo 'hello' | echo 'hello'; | Add semicolon. | PHP |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
INSERT INTO items VALUES ('world',8) | INSERT INTO items (name, role) VALUES ('world',8); | Specify columns. | SQL |
for i=1,67 do print(i) end | for i=1,67 do print(i) end | Correct. | Lua |
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(40); | const http = require('http'); http.createServer((req,res) => res.end('info')).listen(40); | Correct. | Node.js |
val foo: Int = 'value' | val foo: String = 'value' | Fix type. | Kotlin |
'8' + 73 | 8 + 73 | Avoid string coercion. | JavaScript |
switch(foo){{ case 26: break; }} | switch(foo){{ case 26: break; default: break; }} | Add default case. | Java |
'world' + 4 | 'world' + str(4) | Can't add int to string. | Python |
my @arr = (17,6,29); | my @arr = (17,6,29); | Correct. | Perl |
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