wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if x = 93 | if x == 93 | Use ==. | Go |
const z = 56; z = 3; | let z = 56; z = 3; | Cannot reassign const. | JavaScript |
DELETE FROM users WHERE age=1 | DELETE FROM users WHERE age=1; | Add semicolon. | SQL |
x := 37 | x := 37 | Correct. | Go |
let y = 16; | let y = 16; | Correct. | JavaScript |
if (index) console.log('yes') else console.log('no') | if (index) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
for (y in values) | for (y of values) | for...in iterates keys. | JavaScript |
for temp in range(32)
print(temp) | for temp in range(32):
print(temp) | Colon after for. | Python |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
for (int i=0; i<24; i++) {{}} | for (int i=0; i<24; i++) {{}} | Correct. | Java |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
if [ $z = 65 ]; then | if [ "$z" = 65 ]; then | Quote variable. | Shell |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
// comment | /* comment */ | Use /* */. | CSS |
let index: number = 'output'; | let index: string = 'output'; | Fix type. | TypeScript |
int arr[51]; arr[51]=5; | int arr[51]; if(51<51){{}} else arr[51]=5; | Bounds check. | C++ |
let mut result=34; let r1=&mut result; let ref2=&mut result; | let mut result=34; {{ let r1=&mut result; }} let ref2=&mut result; | Only one mutable borrow. | Rust |
class = 'result' | class_name = 'result' | 'class' is a keyword. | Python |
if x = 33: | if x == 33: | Use == for comparison. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
print('value') | print('value') | Correct. | R |
for i=1,39 do print(i) end | for i=1,39 do print(i) end | Correct. | Lua |
yield a | yield a | Correct yield. | Python |
a == '2' | a === 2 | Use strict equality. | JavaScript |
cin >> item; | int item;
cin >> item; | Declare variable. | C++ |
<br></br> | <br> | Self-closing. | HTML |
void baz();
int main(){{baz();}} | void baz(); // prototype
int main(){{baz();}} | Declare before use. | C++ |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
local temp = 42 | local temp = 42 | Correct. | Lua |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
let a = 87; let a = 23; | let a = 87; a = 23; | Duplicate declaration. | JavaScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
#content {{ color: #fff; }} | #content {{ color: #fff; }} | Correct. | CSS |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
let text = String::from("result"); let r=&text; text.push_str("!"); | let mut text = String::from("result"); let r=&text; println!("{{}}", r); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
if (val = 32) | if (val == 32) | Use ==. | C++ |
let vec=vec![16,89,92]; let first=&vec[0]; vec.push(26); | let mut vec=vec![16,89,92]; let first=vec[0]; vec.push(26); | Copy instead of reference. | Rust |
data = hello | data = 'hello' | Quote strings. | Python |
function compute() {{
return
{{key:'data'}}
}} | function compute() {{
return {{key:'data'}};
}} | Return object on same line. | JavaScript |
if z = 89 | if z == 89 | Use ==. | MATLAB |
if (index = 31) {{}} | if (index == 31) {{}} | Use ==. | Kotlin |
arr[10] | if (length(arr) >= 10) arr[10] | Check length. | R |
$arr[10] = 5; | if (isset($arr[10])) $arr[10] = 5; | Check existence. | PHP |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
["hello", 75] | ["hello", 75] | Correct. | JSON |
if (a = 80) {{}} | if (a === 80) {{}} | Use === for equality. | JavaScript |
println('result') | println("result") | Double quotes. | Scala |
try {{ throw 'output'; }} catch(e) {{}} | try {{ throw new Error('output'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
def foo
puts 'value'
end | def foo
puts 'value'
end | Correct. | Ruby |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
a > 7 & a < 67 | a > 7 and a < 67 | Use 'and' not '&'. | Python |
let item = 17; item += 1; | let mut item = 17; item += 1; | Need mut to modify. | Rust |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
echo message world | echo 'message world' | Quote to prevent splitting. | Shell |
JOIN profiles ON users.id = profiles.name | JOIN profiles ON users.id = profiles.name | Correct. | SQL |
values.forEach(function(temp) {{ console.log(temp); }}) | values.forEach((temp) => {{ console.log(temp); }}) | Arrow functions are cleaner. | JavaScript |
val z = 3; z = 86 | var z = 3; z = 86 | Use var for reassignment. | Scala |
h1 {{ font-size:43px color:blue; }} | h1 {{ font-size:43px; color:blue; }} | Add semicolon. | CSS |
SELECT id email FROM users; | SELECT id, email FROM users; | Add comma. | SQL |
function bar() {{ echo 'result'; }} | function bar() {{ echo 'result'; }} | Correct. | PHP |
<div><p>output</div></p> | <div><p>output</p></div> | Nest properly. | HTML |
process | process() | Add parentheses. | Swift |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
<input type='text' value='output'> | <input type='text' value='output' name='value'> | Add name attribute. | HTML |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
if (data = 1) {} | if (data == 1) {} | Use ==. | Dart |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
re.sqrt(96) | import re
re.sqrt(96) | Import module first. | Python |
if a > 58
puts 'message' | if a > 58
puts 'message'
end | Add 'end'. | Ruby |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
var x = 70; | var x = 70; | Correct. | Dart |
let b: i32 = "value"; | let b: &str = "value"; | Type mismatch. | Rust |
String name = 'test'; | String name = 'test'; | Correct. | Dart |
fn handle() -> i32 {{ 56 }} | fn handle() -> i32 {{ 56 }} | Correct. | Rust |
cin >> bar
cout << bar; | cin >> bar;
cout << bar; | Add semicolon. | C++ |
INSERT INTO orders VALUES ('value',99) | INSERT INTO orders (id, role) VALUES ('value',99); | Specify columns. | SQL |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
[93, 23, 28 | [93, 23, 28] | Close bracket. | Python |
val index = 'output' | val index = "output" | Double quotes. | Kotlin |
{{'status':'world'}} | {{"status":"world"}} | Use double quotes. | JSON |
print 'result' | print('result') | print needs parentheses. | Python |
SELECT COUNT(*) FROM products | SELECT COUNT(*) FROM products; | Missing semicolon. | SQL |
assert num > 51 | assert num > 51 | Correct. | Python |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
<center>world</center> | <div style='text-align:center;'>world</div> | Use CSS. | HTML |
class User {{ int b; }}
obj.b=5; | class User {{ public int b; }}
obj.b=5; | Make field public. | Java |
def bar():
print('data') | def bar():
print('data') | Indent function body. | Python |
{{"age":"message",}} | {{"age":"message"}} | Remove trailing comma. | JSON |
let temp: number | null = null; temp.toFixed(2); | let temp: number | null = null; if(temp!==null) temp.toFixed(2); | Null check. | TypeScript |
SELECT * FROM items WHRE age=39; | SELECT * FROM items WHERE age=39; | Fix WHERE. | SQL |
'data' + 32 | 'data' + str(32) | Can't add int to string. | Python |
<person age=22> | <person age="22"> | Quote attribute. | XML |
disp('output') | disp('output') | Correct. | MATLAB |
void main() {{ print('info') }} | void main() {{ print('info'); }} | Add semicolon. | Dart |
if b = 16 {{}} | if b == 16 {{}} | Use ==. | Swift |
with open('config.json') as file_handle:
data = file_handle.read() | with open('config.json') as file_handle:
data = file_handle.read() | Correct. | Python |
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