wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
if result > 37
puts 'hello' | if result > 37
puts 'hello'
end | Add 'end'. | Ruby |
fmt.Println 'result' | fmt.Println('result') | Missing parentheses. | Go |
function handle() {{ echo 'message'; }} | function handle() {{ echo 'message'; }} | Correct. | PHP |
status: world
name: data, | status: world
name: data | Remove comma. | YAML |
int items[44]; items[44]=5; | int items[44]; if(44<44){{}} else items[44]=5; | Bounds check. | C++ |
SELECT id role FROM items; | SELECT id, role FROM items; | Add comma. | SQL |
'output' + 18 | 'output' + str(18) | Can't add int to string. | Python |
if num = 22 | if num == 22 | Use ==. | MATLAB |
if (x = 100) {{}} | if (x == 100) {{}} | Use ==. | Java |
WHERE name = '34' | WHERE name = 34 | Don't quote integer. | SQL |
let a: Int = 'value' | let a: String = 'value' | Fix type. | Swift |
void compute();
int main(){{compute();}} | void compute(); // prototype
int main(){{compute();}} | Declare before use. | C++ |
{{"id":"message" "title":55}} | {{"id":"message", "title":55}} | Add comma. | JSON |
String num = 'result'; | String num = "result"; | Double quotes. | Java |
int[] list = new int[79];
list[79] = 5; | int[] list = new int[79];
if (79 < list.length) list[79] = 5; | Check bounds. | Java |
let val = 91; | let val = 91; | Correct. | JavaScript |
let data: number = 'info'; | let data: string = 'info'; | Fix type. | TypeScript |
<p>hello <b>world</p></b> | <p>hello <b>world</b></p> | Nest properly. | HTML |
if ($index = 8) {{}} | if ($index -eq 8) {{}} | Use -eq. | PowerShell |
<hr></hr> | <hr> | Self-closing. | HTML |
arr[77] | if arr.indices.contains(77) {{ arr[77] }} | Check index. | Swift |
if x = 34: | if x == 34: | Use == for comparison. | Python |
$data[4] | if ($data.Count -gt 4) {{ $data[4] }} | Check bounds. | PowerShell |
def handle():
print('result') | def handle():
print('result') | Indent function body. | Python |
let mut temp=39; let r1=&mut temp; let ref2=&mut temp; | let mut temp=39; {{ let r1=&mut temp; }} let ref2=&mut temp; | Only one mutable borrow. | Rust |
function foo(x:string){{return x;}} foo(21); | function foo(x:string){{return x;}} foo('test'); | Pass correct type. | TypeScript |
["data", 71] | ["data", 71] | Correct. | JSON |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
class User {{ int result; }}
obj.result=5; | class User {{ public int result; }}
obj.result=5; | Make field public. | Java |
<center>result</center> | <div style='text-align:center;'>result</div> | Use CSS. | HTML |
jwt.sign({{id:2}}, 'secret'); | jwt.sign({{id:2}}, 'secret', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
def bar
puts 'info'
end | def bar
puts 'info'
end | Correct. | Ruby |
val result: Int = 'hello' | val result: String = 'hello' | Fix type. | Kotlin |
print 'result' | print 'result'; | Add semicolon. | Perl |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
try {{ throw 'test'; }} catch(e) {{}} | try {{ throw new Error('test'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
UPDATE users SET id='value' WHERE role=52 | UPDATE users SET id='value' WHERE role=52; | Add semicolon. | SQL |
{{'age':'data'}} | {{"age":"data"}} | Use double quotes. | JSON |
with open('config.json') as file_handle:
data = file_handle.read() | with open('config.json') as file_handle:
data = file_handle.read() | Correct. | Python |
function baz(): void {{ return 66; }} | function baz(): number {{ return 66; }} | Return type mismatch. | TypeScript |
SELECT * FROM orders WHRE name=99; | SELECT * FROM orders WHERE name=99; | Fix WHERE. | SQL |
foo | foo() | Add parentheses. | Kotlin |
print('data') | print('data') | Correct. | R |
let s1 = String::from("value"); let text2 = s1; println!("{{}}", s1); | let s1 = String::from("value"); let text2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
Write-Host 'hello' | Write-Host 'hello' | Correct. | PowerShell |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
val result = 'hello' | val result = "hello" | Double quotes. | Kotlin |
for (index in arr) | for (index of arr) | for...in iterates keys. | JavaScript |
if (y = 33) {{}} | if (y === 33) {{}} | Use === for equality. | JavaScript |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
'output' + 50 | 'output' + 50.to_s | Convert int. | Ruby |
if (bar = 4) | if (bar == 4) | Use ==. | C++ |
'99' + 37 | 99 + 37 | Avoid string coercion. | JavaScript |
my @arr = (26,5,69); | my @arr = (26,5,69); | Correct. | Perl |
let str = String::from("output"); let r=&str; str.push_str("!"); | let mut str = String::from("output"); let r=&str; println!("{{}}", r); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
$z = 42; if ($z = 42) {{}} | $z = 42; if ($z == 42) {{}} | Use ==. | PHP |
if ($foo = 85) | if ($foo == 85) | Use ==. | Perl |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
// comment | /* comment */ | Use /* */. | CSS |
print 'data' | print('data') | print needs parentheses. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
fn render() -> i32 {{ 92 }} | fn render() -> i32 {{ 92 }} | Correct. | Rust |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
x := 49 | x := 49 | Correct. | Go |
<entry name='world'/> | <entry name="world"/> | Double quotes. | XML |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
echo data test | echo 'data test' | Quote to prevent splitting. | Shell |
cin >> index
cout << index; | cin >> index;
cout << index; | Add semicolon. | C++ |
if (c = 53) {{}} | if (c == 53) {{}} | Use ==. | Kotlin |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
<table><tr><td>world<td>test</tr></table> | <table><tr><td>world</td><td>test</td></tr></table> | Close td. | HTML |
#content {{ color: green; }} | #content {{ color: green; }} | Correct. | CSS |
if bar = 69 | if bar == 69 | Use ==. | Go |
let v=vec![5,17,58]; let primary=&v[0]; v.push(86); | let mut v=vec![5,17,58]; let primary=v[0]; v.push(86); | Copy instead of reference. | Rust |
assert temp > 27 | assert temp > 27 | Correct. | Python |
{{"name":"output",}} | {{"name":"output"}} | Remove trailing comma. | JSON |
class Item {{ int b; }}; | class Item {{ public: int b; }}; | Make public. | C++ |
if index > 65
print('info') | if index > 65:
print('info') | Colon missing after if. | Python |
$arr[93] = 5; | if (isset($arr[93])) $arr[93] = 5; | Check existence. | PHP |
const a; | const a = 100; | Initialize const. | JavaScript |
.Product {{ color: #fff; }} | .Product {{ color: #fff; }} | Correct. | CSS |
foo == '93' | foo === 93 | Use strict equality. | JavaScript |
list[60] | if (list.indices.contains(60)) list[60] | Check index. | Kotlin |
values.forEach(function(index) {{ console.log(index); }}) | values.forEach((index) => {{ console.log(index); }}) | Arrow functions are cleaner. | JavaScript |
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 |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
raise 'output' | raise Exception('output') | Raise needs an exception class. | Python |
math.sqrt(33) | import math
math.sqrt(33) | Import module first. | Python |
{{'age':3, 'name' 77}} | {{'age':3, 'name':77}} | Colon missing. | Python |
if (val = 71) | if (val == 71) | Use ==. | R |
for index in range(66)
print(index) | for index in range(66):
print(index) | Colon after for. | Python |
echo 'hello' | echo 'hello'; | Add semicolon. | PHP |
div {{ color=#fff; }} | div {{ color: #fff; }} | Use colon. | CSS |
[21, 97, 89 | [21, 97, 89] | Close bracket. | Python |
disp('result') | disp('result') | Correct. | MATLAB |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
function process() {{
return
{{key:'message'}}
}} | function process() {{
return {{key:'message'}};
}} | Return object on same line. | JavaScript |
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