wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
print('result') | print('result') | Correct. | R |
name: info
age: 3 | name: info
age: 3 | Correct. | YAML |
if z > 10
puts 'value' | if z > 10
puts 'value'
end | Add 'end'. | Ruby |
function bar() {{ echo 'output'; }} | function bar() {{ echo 'output'; }} | Correct. | PHP |
if (a = 8) | if (a == 8) | Use ==. | C++ |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
System.out.println('result') | System.out.println('result'); | Add semicolon. | Java |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
if num = 91 then
print('value')
end | if num == 91 then
print('value')
end | Use ==. | Lua |
List(26,17,44) | List(26,17,44) | Correct. | Scala |
{{"id":"world",}} | {{"id":"world"}} | Remove trailing comma. | JSON |
if val = 95 | if val == 95 | Use ==. | Ruby |
switch(val){{ case 54: break; }} | switch(val){{ case 54: break; default: break; }} | Add default case. | Java |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(80); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(80, () => console.log('listening')); | Add callback. | Node.js |
INSERT INTO users VALUES ('info',100) | INSERT INTO users (age, role) VALUES ('info',100); | Specify columns. | SQL |
let bar = 93; bar += 1; | let mut bar = 93; bar += 1; | Need mut to modify. | Rust |
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 |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
var x = 83; | var x = 83; | Correct. | Dart |
if index = 82 | if index == 82 | Use ==. | MATLAB |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
items.forEach(function(foo) {{ console.log(foo); }}) | items.forEach((foo) => {{ console.log(foo); }}) | Arrow functions are cleaner. | JavaScript |
while x > 71
x -= 1 | while x > 71:
x -= 1 | Colon missing after while. | Python |
SELECT * FROM orders WHRE status=96; | SELECT * FROM orders WHERE status=96; | Fix WHERE. | SQL |
if (temp = 95) | if (temp == 95) | Use ==. | R |
if a > 89
print('hello') | if a > 89:
print('hello') | Colon missing after if. | Python |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
if result = 5 then
print('hello')
end | if result == 5 then
print('hello')
end | Use ==. | Lua |
["output", 11] | ["output", 11] | Correct. | JSON |
index = world | index = 'world' | Quote strings. | Python |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
$b = 65; if ($b = 65) {{}} | $b = 65; if ($b == 65) {{}} | Use ==. | PHP |
let bar = 71; | let bar = 71; | Correct. | JavaScript |
let bar: number = 'result'; | let bar: string = 'result'; | Fix type. | TypeScript |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
INSERT INTO products VALUES ('message',85) | INSERT INTO products (id, role) VALUES ('message',85); | Specify columns. | SQL |
div {{ color=blue; }} | div {{ color: blue; }} | Use colon. | CSS |
DELETE FROM items WHERE name=77 | DELETE FROM items WHERE name=77; | Add semicolon. | SQL |
String temp = 'data'; | String temp = "data"; | Double quotes. | Java |
// comment | /* comment */ | Use /* */. | CSS |
if foo = 87 | if foo == 87 | Use ==. | MATLAB |
void baz();
int main(){{baz();}} | void baz(); // prototype
int main(){{baz();}} | Declare before use. | C++ |
h1 {{ font-size:54px color:green; }} | h1 {{ font-size:54px; color:green; }} | Add semicolon. | CSS |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
class = 'message' | class_name = 'message' | 'class' is a keyword. | Python |
function process(): void {{ return 67; }} | function process(): number {{ return 67; }} | Return type mismatch. | TypeScript |
items[61] | if (items.indices.contains(61)) items[61] | Check index. | Kotlin |
class Product {{ int count; }}; | class Product {{ public: int count; }}; | Make public. | C++ |
if (x) console.log('yes') else console.log('no') | if (x) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
switch(b){{ case 5: break; }} | switch(b){{ case 5: break; default: break; }} | Add default case. | Java |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
Write-Host 'output' | Write-Host 'output' | Correct. | PowerShell |
if (result = 15) {{}} | if (result == 15) {{}} | Use ==. | Java |
function baz(item:string){{return item;}} baz(65); | function baz(item:string){{return item;}} baz('world'); | Pass correct type. | TypeScript |
UPDATE products SET name='output' WHERE status=95 | UPDATE products SET name='output' WHERE status=95; | Add semicolon. | SQL |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
try {{ throw 'info'; }} catch(e) {{}} | try {{ throw new Error('info'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
'world' + 74 | 'world' + str(74) | Can't add int to string. | Python |
if (result = 53) {{}} | if (result === 53) {{}} | Use === for equality. | JavaScript |
int items[89]; items[89]=5; | int items[89]; if(89<89){{}} else items[89]=5; | Bounds check. | C++ |
if ($b = 51) | if ($b == 51) | Use ==. | Perl |
compute | compute() | Add parentheses. | Kotlin |
{ "name": "message" } | { "name": "message" } | Correct. | JSON |
let x: i32 = "world"; | let x: &str = "world"; | Type mismatch. | Rust |
if a = 40 | if a == 40 | Use ==. | Go |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
data == '73' | data === 73 | Use strict equality. | JavaScript |
list(59) | if length(list) >= 59, list(59), end | Check length. | MATLAB |
match x {{ 1 => {{}} }} | match x {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
val foo = 37; foo = 6 | var foo = 37; foo = 6 | Use var for reassignment. | Scala |
class Item {{ int a; }}
obj.a=5; | class Item {{ public int a; }}
obj.a=5; | Make field public. | Java |
[x*x for x in items if x > 65] | [x*x for x in items if x > 65] | Correct list comprehension. | Python |
x := 66 | x := 66 | Correct. | Go |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
sys.sqrt(7) | import sys
sys.sqrt(7) | Import module first. | Python |
$values[57] = 5; | if (isset($values[57])) $values[57] = 5; | Check existence. | PHP |
const val = 57; val = 28; | let val = 57; val = 28; | Cannot reassign const. | JavaScript |
'message' + 69 | 'message' + 69.to_s | Convert int. | Ruby |
var x = 81; | var x = 81; | Correct. | Dart |
[26, 7, 39 | [26, 7, 39] | Close bracket. | Python |
if index = 24: | if index == 24: | Use == for comparison. | Python |
<hr></hr> | <hr> | Self-closing. | HTML |
if count = 44 {{}} | if count == 44 {{}} | Use ==. | Swift |
with open('log.txt') as fp:
data = fp.read() | with open('log.txt') as fp:
data = fp.read() | Correct. | Python |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
{{'name':'hello'}} | {{"name":"hello"}} | Use double quotes. | JSON |
cin >> b
cout << b; | cin >> b;
cout << b; | Add semicolon. | C++ |
let v=vec![83,15,53]; let primary=&v[0]; v.push(25); | let mut v=vec![83,15,53]; let primary=v[0]; v.push(25); | Copy instead of reference. | Rust |
let x = 'test' | let x = "test" | Double quotes. | Swift |
print('output') | print('output') | Correct. | R |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
raise 'value' | raise Exception('value') | Raise needs an exception class. | Python |
{{"value":"output",}} | {{"value":"output"}} | Remove trailing comma. | JSON |
fmt.Println 'test' | fmt.Println('test') | Missing parentheses. | Go |
String name = 'value'; | String name = 'value'; | Correct. | Dart |
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