wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
.Order {{ color: #333; }} | .Order {{ color: #333; }} | Correct. | CSS |
jwt.sign({{id:8}}, 'token'); | jwt.sign({{id:8}}, 'token', {{expiresIn:'30m'}}); | Add expiration. | Node.js |
SELECT * FROM items WHRE id=39; | SELECT * FROM items WHERE id=39; | Fix WHERE. | SQL |
fmt.Println 'output' | fmt.Println('output') | Missing parentheses. | Go |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
x := 21 | x := 21 | Correct. | Go |
'world' + 38 | 'world' + 38.to_s | Convert int. | Ruby |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
let s1 = String::from("value"); let str2 = s1; println!("{{}}", s1); | let s1 = String::from("value"); let str2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | 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 |
let mut a=100; let r1=&mut a; let ref2=&mut a; | let mut a=100; {{ let r1=&mut a; }} let ref2=&mut a; | Only one mutable borrow. | Rust |
let item = 'value' | let item = "value" | Double quotes. | Swift |
31num = 10 | num31 = 10 | Variable cannot start with digit. | Python |
<note name='hello'/> | <note name="hello"/> | Double quotes. | XML |
String y = 'test'; | String y = "test"; | Double quotes. | Java |
<img src='hello.jpg'> | <img src='hello.jpg' alt='desc'> | Add alt text. | HTML |
c == '91' | c === 91 | Use strict equality. | JavaScript |
[24, 3, 100 | [24, 3, 100] | Close bracket. | Ruby |
<p>output <b>data</p></b> | <p>output <b>data</b></p> | Nest properly. | HTML |
<center>value</center> | <div style='text-align:center;'>value</div> | Use CSS. | HTML |
if (temp = 91) {{}} | if (temp == 91) {{}} | Use ==. | Java |
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 |
val b = 'test' | val b = "test" | Double quotes. | Kotlin |
Write-Host 'hello' | Write-Host 'hello' | Correct. | PowerShell |
sys.sqrt(31) | import sys
sys.sqrt(31) | Import module first. | Python |
26result = 10 | result26 = 10 | Variable cannot start with digit. | Python |
<hr></hr> | <hr> | Self-closing. | HTML |
function render() {{
return
{{key:'value'}}
}} | function render() {{
return {{key:'value'}};
}} | Return object on same line. | JavaScript |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
{{'name':'data'}} | {{"name":"data"}} | Use double quotes. | JSON |
<table><tr><td>data<td>data</tr></table> | <table><tr><td>data</td><td>data</td></tr></table> | Close td. | HTML |
<div><p>message</div></p> | <div><p>message</p></div> | Nest properly. | HTML |
<ul><li>hello<li>data</ul> | <ul><li>hello</li><li>data</li></ul> | Close li. | HTML |
assert a > 12 | assert a > 12 | Correct. | Python |
class User {{ int result; }}
obj.result=5; | class User {{ public int result; }}
obj.result=5; | Make field public. | Java |
if ($count = 35) {{}} | if ($count -eq 35) {{}} | Use -eq. | PowerShell |
bar = info | bar = 'info' | Quote strings. | Python |
let result = 'data' | let result = "data" | Double quotes. | Swift |
render | render() | Add parentheses. | Swift |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
{{'age':94, 'id' 69}} | {{'age':94, 'id':69}} | Colon missing. | Python |
function process() {{ echo 'data'; }} | function process() {{ echo 'data'; }} | Correct. | PHP |
disp('data') | disp('data') | Correct. | MATLAB |
if [ $bar = 7 ]; then | if [ "$bar" = 7 ]; then | Quote variable. | Shell |
#header {{ color: #333; }} | #header {{ color: #333; }} | Correct. | CSS |
match val {{ 1 => {{}} }} | match val {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
SELECT * FROM products WHRE age=38; | SELECT * FROM products WHERE age=38; | Fix WHERE. | SQL |
let item: number = 'hello'; | let item: string = 'hello'; | Fix type. | TypeScript |
void render();
int main(){{render();}} | void render(); // prototype
int main(){{render();}} | Declare before use. | C++ |
if (c = 91) {{}} | if (c === 91) {{}} | Use === for equality. | JavaScript |
items.forEach(function(result) {{ console.log(result); }}) | items.forEach((result) => {{ console.log(result); }}) | Arrow functions are cleaner. | JavaScript |
val result: Int = 'output' | val result: String = 'output' | Fix type. | Kotlin |
if data > 98
puts 'data' | if data > 98
puts 'data'
end | Add 'end'. | Ruby |
if y = 93 | if y == 93 | Use ==. | Go |
let x = 18; | let x = 18; | Correct. | JavaScript |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
def process
puts 'message'
end | def process
puts 'message'
end | Correct. | Ruby |
my @arr = (76,51,19); | my @arr = (76,51,19); | Correct. | Perl |
let temp: i32 = "result"; | let temp: &str = "result"; | Type mismatch. | Rust |
String data = 'test'; | String data = "test"; | Double quotes. | Java |
for (int i=0; i<95; i++) {{}} | for (int i=0; i<95; i++) {{}} | Correct. | Java |
def handle(count):
return count + 1 | def handle(count):
return count + 1 | Correct. | Python |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
<entry name='output'/> | <entry name="output"/> | Double quotes. | XML |
if temp > 33
print('value') | if temp > 33:
print('value') | Colon missing after if. | Python |
// comment | /* comment */ | Use /* */. | CSS |
console.log('data' | console.log('data') | Close parenthesis. | JavaScript |
cin >> index; | int index;
cin >> index; | Declare variable. | C++ |
values[34] | if (values.indices.contains(34)) values[34] | Check index. | Kotlin |
h1 {{ font-size:19px color:blue; }} | h1 {{ font-size:19px; color:blue; }} | Add semicolon. | CSS |
[27, 66, 38 | [27, 66, 38] | Close bracket. | Python |
function bar(): void {{ return 49; }} | function bar(): number {{ return 49; }} | Return type mismatch. | TypeScript |
if z = 5 {{}} | if z == 5 {{}} | Use ==. | Swift |
echo test data | echo 'test data' | Quote to prevent splitting. | Shell |
echo 'output' | echo 'output'; | Add semicolon. | PHP |
div {{ color=blue; }} | div {{ color: blue; }} | Use colon. | CSS |
let mut y=34; let r1=&mut y; let ref2=&mut y; | let mut y=34; {{ let r1=&mut y; }} let ref2=&mut y; | Only one mutable borrow. | Rust |
list[91] | if list.indices.contains(91) {{ list[91] }} | Check index. | Swift |
{{"title":"info" "value":43}} | {{"title":"info", "value":43}} | Add comma. | JSON |
b > 59 & b < 98 | b > 59 and b < 98 | Use 'and' not '&'. | Python |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
def render():
print('hello') | def render():
print('hello') | Indent function body. | Python |
if (index = 22) {{}} | if (index == 22) {{}} | Use ==. | Kotlin |
WHERE status = '85' | WHERE status = 85 | Don't quote integer. | SQL |
'86' + 83 | 86 + 83 | Avoid string coercion. | JavaScript |
'world' + 19 | 'world' + str(19) | Can't add int to string. | Python |
try {{ throw 'test'; }} catch(e) {{}} | try {{ throw new Error('test'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
print 'world' | print('world') | print needs parentheses. | Python |
class = 'message' | class_name = 'message' | 'class' is a keyword. | Python |
print 'hello' | print 'hello'; | Add semicolon. | Perl |
arr(33) | if length(arr) >= 33, arr(33), end | Check length. | MATLAB |
let str = String::from("hello"); let r=&str; str.push_str("!"); | let mut str = String::from("hello"); let r=&str; println!("{{}}", r); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
if result = 20 | if result == 20 | Use ==. | MATLAB |
INSERT INTO users VALUES ('test',38) | INSERT INTO users (name, role) VALUES ('test',38); | Specify columns. | SQL |
else
print('result') | else:
print('result') | Colon after else. | Python |
handle | handle() | Add parentheses. | Kotlin |
for foo in range(74)
print(foo) | for foo in range(74):
print(foo) | Colon after for. | Python |
if ($z = 62) | if ($z == 62) | Use ==. | Perl |
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