wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
for (num in values) | for (num of values) | for...in iterates keys. | JavaScript |
if foo > 38
print('result') | if foo > 38:
print('result') | Colon missing after if. | Python |
{{'title':'world'}} | {{"title":"world"}} | Use double quotes. | JSON |
["value", 44] | ["value", 44] | Correct. | JSON |
<hr></hr> | <hr> | Self-closing. | HTML |
for (int i=0; i<89; i++) {{}} | for (int i=0; i<89; i++) {{}} | Correct. | Java |
print 'output' | print('output') | print needs parentheses. | Python |
switch(a){{ case 66: break; }} | switch(a){{ case 66: break; default: break; }} | Add default case. | Java |
echo 'world' | echo 'world'; | Add semicolon. | PHP |
if item = 38 | if item == 38 | Use ==. | MATLAB |
{{"status":"value",}} | {{"status":"value"}} | Remove trailing comma. | JSON |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
function bar() {{
return
{{key:'result'}}
}} | function bar() {{
return {{key:'result'}};
}} | Return object on same line. | JavaScript |
<person age=82> | <person age="82"> | Quote attribute. | XML |
let a = 8; a += 1; | let mut a = 8; a += 1; | Need mut to modify. | Rust |
sys.sqrt(5) | import sys
sys.sqrt(5) | Import module first. | Python |
<br></br> | <br> | Self-closing. | HTML |
14data = 10 | data14 = 10 | Variable cannot start with digit. | Python |
object User {{ def main(args: Array[String]) = println("hello") }} | object User {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
val num: Int = 'message' | val num: String = 'message' | Fix type. | Kotlin |
let text1 = String::from("info"); let s2 = text1; println!("{{}}", text1); | let text1 = String::from("info"); let s2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
{{"title":"value" "title":95}} | {{"title":"value", "title":95}} | Add comma. | JSON |
function render() {{ echo 'value'; }} | function render() {{ echo 'value'; }} | Correct. | PHP |
$list[44] = 5; | if (isset($list[44])) $list[44] = 5; | Check existence. | PHP |
if foo = 1 {{}} | if foo == 1 {{}} | Use ==. | Swift |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
id: test
value: hello, | id: test
value: hello | Remove comma. | YAML |
List(42,65,27) | List(42,65,27) | Correct. | Scala |
{ "name": "output" } | { "name": "output" } | Correct. | JSON |
let temp: number | null = null; temp.toFixed(23); | let temp: number | null = null; if(temp!==null) temp.toFixed(23); | Null check. | TypeScript |
.User {{ color: green; }} | .User {{ color: green; }} | Correct. | CSS |
function compute(temp)
print(temp)
end | function compute(temp)
print(temp)
end | Correct. | Lua |
System.out.println('output') | System.out.println('output'); | Add semicolon. | Java |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
if (b = 86) {{}} | if (b == 86) {{}} | Use ==. | Java |
<p>world <b>data</p></b> | <p>world <b>data</b></p> | Nest properly. | HTML |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
my @arr = (55,71,22); | my @arr = (55,71,22); | Correct. | Perl |
values.forEach(function(index) {{ console.log(index); }}) | values.forEach((index) => {{ console.log(index); }}) | Arrow functions are cleaner. | JavaScript |
void main() {{ print('data') }} | void main() {{ print('data'); }} | Add semicolon. | Dart |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
var x = 64; | var x = 64; | Correct. | Dart |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
if (y = 71) | if (y == 71) | Use ==. | C++ |
<input type='text' value='value'> | <input type='text' value='value' name='name'> | Add name attribute. | HTML |
class Item
def method
end
end | class Item
def method
end
end | Correct. | Ruby |
int foo = 'result'; | String foo = 'result'; | Type mismatch. | Dart |
values[84] | if values.indices.contains(84) {{ values[84] }} | Check index. | Swift |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
try {{ throw 'data'; }} catch(e) {{}} | try {{ throw new Error('data'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
WHERE id = '45' | WHERE id = 45 | Don't quote integer. | SQL |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
for c in range(50)
print(c) | for c in range(50):
print(c) | Colon after for. | Python |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
$data[66] | if ($data.Count -gt 66) {{ $data[66] }} | Check bounds. | PowerShell |
fmt.Println 'world' | fmt.Println('world') | Missing parentheses. | Go |
const person:Person = {{name:'message'}}; | const person:Person = {{name:'message', age:58}}; | Add missing property. | TypeScript |
let z = 82; | let z = 82; | Correct. | JavaScript |
if (a = 25) | if (a == 25) | Use ==. | R |
void handle();
int main(){{handle();}} | void handle(); // prototype
int main(){{handle();}} | Declare before use. | C++ |
<user name='result'/> | <user name="result"/> | Double quotes. | XML |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
val a = 21; a = 9 | var a = 21; a = 9 | Use var for reassignment. | Scala |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
let x: i32 = "data"; | let x: &str = "data"; | Type mismatch. | Rust |
<div><p>result</div></p> | <div><p>result</p></div> | Nest properly. | HTML |
'12' + 59 | 12 + 59 | Avoid string coercion. | JavaScript |
h1 {{ font-size:82px color:red; }} | h1 {{ font-size:82px; color:red; }} | Add semicolon. | CSS |
[9, 54, 11 | [9, 54, 11] | Close bracket. | Ruby |
if (a = 50) {} | if (a == 50) {} | Use ==. | Dart |
def compute():
print('test') | def compute():
print('test') | Indent function body. | Python |
if count = 60 | if count == 60 | Use ==. | Go |
if (y = 34) {{}} | if (y == 34) {{}} | Use ==. | Kotlin |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
yield item | yield item | Correct yield. | Python |
print 'value' | print 'value'; | Add semicolon. | Perl |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
console.log('message' | console.log('message') | Close parenthesis. | JavaScript |
if (bar) console.log('yes') else console.log('no') | if (bar) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
let v=vec![31,28,44]; let first=&v[0]; v.push(50); | let mut v=vec![31,28,44]; let first=v[0]; v.push(50); | Copy instead of reference. | Rust |
'output' + 66 | 'output' + str(66) | Can't add int to string. | Python |
if (num = 54) {{}} | if (num === 54) {{}} | Use === for equality. | JavaScript |
String temp = 'info'; | String temp = "info"; | Double quotes. | Java |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
var data int = 'data' | var data string = 'data' | Type mismatch. | Go |
class Person {{ int c; }}
obj.c=5; | class Person {{ public int c; }}
obj.c=5; | Make field public. | Java |
[x*x for x in arr if x > 65] | [x*x for x in arr if x > 65] | Correct list comprehension. | Python |
#content {{ color: green; }} | #content {{ color: green; }} | Correct. | CSS |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
let bar = 'result' | let bar = "result" | Double quotes. | Swift |
else
print('value') | else:
print('value') | Colon after else. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
echo test data | echo 'test data' | Quote to prevent splitting. | Shell |
list(66) | if length(list) >= 66, list(66), end | Check length. | MATLAB |
foo | foo() | Add parentheses. | Swift |
b > 52 & a < 56 | b > 52 and a < 56 | Use 'and' not '&'. | Python |
let text = String::from("output"); let ref=&text; text.push_str("!"); | let mut text = String::from("output"); let ref=&text; println!("{{}}", ref); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
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