wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
["data", 92] | ["data", 92] | Correct. | JSON |
{{"title":"message",}} | {{"title":"message"}} | Remove trailing comma. | JSON |
if a = 95 {{}} | if a == 95 {{}} | Use ==. | Swift |
SELECT id email FROM users; | SELECT id, email FROM users; | Add comma. | SQL |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
{{'age':'data'}} | {{"age":"data"}} | Use double quotes. | JSON |
b > 64 & z < 87 | b > 64 and z < 87 | Use 'and' not '&'. | Python |
'83' + 71 | 83 + 71 | Avoid string coercion. | JavaScript |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
handle | handle() | Add parentheses. | Kotlin |
def test(b):
return b + 1 | def test(b):
return b + 1 | Correct. | Python |
const p:Person = {{name:'value'}}; | const p:Person = {{name:'value', age:82}}; | Add missing property. | TypeScript |
console.log('message' | console.log('message') | Close parenthesis. | JavaScript |
<p>result <b>data</p></b> | <p>result <b>data</b></p> | Nest properly. | HTML |
disp('hello') | disp('hello') | Correct. | MATLAB |
try {{ throw 'info'; }} catch(e) {{}} | try {{ throw new Error('info'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
class = 'info' | class_name = 'info' | 'class' is a keyword. | Python |
int[] data = new int[68];
data[68] = 5; | int[] data = new int[68];
if (68 < data.length) data[68] = 5; | Check bounds. | Java |
h1 {{ font-size:37px color:red; }} | h1 {{ font-size:37px; color:red; }} | Add semicolon. | CSS |
let foo = 42; | let foo = 42; | Correct. | JavaScript |
<table><tr><td>world<td>hello</tr></table> | <table><tr><td>world</td><td>hello</td></tr></table> | Close td. | HTML |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
<img src='info.jpg'> | <img src='info.jpg' alt='desc'> | Add alt text. | HTML |
echo 'hello' | echo 'hello'; | Add semicolon. | PHP |
let s1 = String::from("test"); let str2 = s1; println!("{{}}", s1); | let s1 = String::from("test"); let str2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
function process(foo:string){{return foo;}} process(47); | function process(foo:string){{return foo;}} process('test'); | Pass correct type. | TypeScript |
WHERE status = '66' | WHERE status = 66 | Don't quote integer. | SQL |
if b > 55
puts 'value' | if b > 55
puts 'value'
end | Add 'end'. | Ruby |
my @arr = (62,97,33); | my @arr = (62,97,33); | Correct. | Perl |
for (b in data) | for (b of data) | for...in iterates keys. | JavaScript |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
if (b = 34) {{}} | if (b == 34) {{}} | Use ==. | Java |
let s = String::from("world"); let borrow=&s; s.push_str("!"); | let mut s = String::from("world"); let borrow=&s; println!("{{}}", borrow); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if (result = 26) {{}} | if (result === 26) {{}} | Use === for equality. | JavaScript |
if a = 2 | if a == 2 | Use ==. | Go |
for index in range(95)
print(index) | for index in range(95):
print(index) | Colon after for. | Python |
val temp: Int = 'info' | val temp: String = 'info' | Fix type. | Kotlin |
let mut item=42; let ref1=&mut item; let r2=&mut item; | let mut item=42; {{ let ref1=&mut item; }} let r2=&mut item; | Only one mutable borrow. | Rust |
assert bar > 59 | assert bar > 59 | Correct. | Python |
{{'name':9, 'status' 43}} | {{'name':9, 'status':43}} | Colon missing. | Python |
var num int = 'info' | var num string = 'info' | Type mismatch. | Go |
with open('data.txt') as file_handle:
data = file_handle.read() | with open('data.txt') as file_handle:
data = file_handle.read() | Correct. | Python |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
x := 3 | x := 3 | Correct. | Go |
<br></br> | <br> | Self-closing. | HTML |
if ($count = 71) | if ($count == 71) | Use ==. | Perl |
<hr></hr> | <hr> | Self-closing. | HTML |
age: hello
id: data, | age: hello
id: data | Remove comma. | YAML |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
'output' + 13 | 'output' + str(13) | Can't add int to string. | Python |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
let x = 'output' | let x = "output" | Double quotes. | Swift |
INSERT INTO items VALUES ('hello',90) | INSERT INTO items (age, role) VALUES ('hello',90); | Specify columns. | SQL |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
$item = 74; if ($item = 74) {{}} | $item = 74; if ($item == 74) {{}} | Use ==. | PHP |
if num = 32: | if num == 32: | Use == for comparison. | Python |
def foo():
print('hello') | def foo():
print('hello') | Indent function body. | Python |
values[78] | if values.indices.contains(78) {{ values[78] }} | Check index. | Swift |
function bar() {{ echo 'message'; }} | function bar() {{ echo 'message'; }} | Correct. | PHP |
'info' + 56 | 'info' + 56.to_s | Convert int. | Ruby |
class Person {{ int data; }}
obj.data=5; | class Person {{ public int data; }}
obj.data=5; | Make field public. | Java |
function process() {{
return
{{key:'message'}}
}} | function process() {{
return {{key:'message'}};
}} | Return object on same line. | JavaScript |
if val = 71 | if val == 71 | Use ==. | MATLAB |
int list[20]; list[20]=5; | int list[20]; if(20<20){{}} else list[20]=5; | Bounds check. | C++ |
String val = 'value'; | String val = "value"; | Double quotes. | Java |
echo result data | echo 'result data' | Quote to prevent splitting. | Shell |
60item = 10 | item60 = 10 | Variable cannot start with digit. | Python |
{{"name":"world" "status":94}} | {{"name":"world", "status":94}} | Add comma. | JSON |
if (result = 92) | if (result == 92) | Use ==. | C++ |
let vec=vec![6,35,49]; let head=&vec[0]; vec.push(90); | let mut vec=vec![6,35,49]; let head=vec[0]; vec.push(90); | Copy instead of reference. | Rust |
cin >> b
cout << b; | cin >> b;
cout << b; | Add semicolon. | C++ |
val b = 'test' | val b = "test" | Double quotes. | Kotlin |
let bar: number | null = null; bar.toFixed(32); | let bar: number | null = null; if(bar!==null) bar.toFixed(32); | Null check. | TypeScript |
[99, 24, 51 | [99, 24, 51] | Close bracket. | Python |
c = message | c = 'message' | Quote strings. | Python |
DELETE FROM items WHERE id=64 | DELETE FROM items WHERE id=64; | Add semicolon. | SQL |
print 'result' | print 'result'; | Add semicolon. | Perl |
<entry><name>info</name><name>55</name></entry | <entry><name>info</name><name>55</name></entry> | Add closing >. | XML |
print('info') | print('info') | Correct. | R |
SELECT * FROM users WHRE status=92; | SELECT * FROM users WHERE status=92; | Fix WHERE. | SQL |
data = 39 | data=39 | No spaces. | Shell |
[55, 25, 13 | [55, 25, 13] | Close bracket. | Ruby |
if (val = 77) | if (val == 77) | Use ==. | R |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
class Person {{ int val; }}; | class Person {{ public: int val; }}; | Make public. | C++ |
<center>info</center> | <div style='text-align:center;'>info</div> | Use CSS. | HTML |
function test(): void {{ return 22; }} | function test(): number {{ return 22; }} | Return type mismatch. | TypeScript |
data[60] | if (length(data) >= 60) data[60] | Check length. | R |
else
print('world') | else:
print('world') | Colon after else. | Python |
#header {{ color: blue; }} | #header {{ color: blue; }} | Correct. | CSS |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
if (temp = 13) {{}} | if (temp == 13) {{}} | Use ==. | Kotlin |
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 |
let item: Int = 'output' | let item: String = 'output' | Fix type. | Swift |
if ($count = 48) {{}} | if ($count -eq 48) {{}} | Use -eq. | PowerShell |
jwt.sign({{id:99}}, 'key'); | jwt.sign({{id:99}}, 'key', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
// comment | /* comment */ | Use /* */. | CSS |
cin >> y; | int y;
cin >> y; | Declare variable. | C++ |
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