wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if (val = 16) {{}} | if (val == 16) {{}} | Use ==. | Kotlin |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
let y: Int = 'info' | let y: String = 'info' | Fix type. | Swift |
val result = 'test' | val result = "test" | Double quotes. | Kotlin |
let data = 44; let data = 46; | let data = 44; data = 46; | Duplicate declaration. | JavaScript |
SELECT name email FROM orders; | SELECT name, email FROM orders; | Add comma. | SQL |
age: info
status: hello, | age: info
status: hello | Remove comma. | YAML |
print 'world' | print('world') | print needs parentheses. | Python |
var x = 7; | var x = 7; | Correct. | Dart |
if (bar) console.log('yes') else console.log('no') | if (bar) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
["world", 88] | ["world", 88] | Correct. | JSON |
foo | foo() | Add parentheses. | Kotlin |
if c = 78 | if c == 78 | Use ==. | Go |
for (int i=0; i<71; i++) {{}} | for (int i=0; i<71; i++) {{}} | Correct. | Java |
$arr[86] = 5; | if (isset($arr[86])) $arr[86] = 5; | Check existence. | PHP |
<div><p>info</div></p> | <div><p>info</p></div> | Nest properly. | HTML |
if (index = 47) {{}} | if (index == 47) {{}} | Use ==. | Java |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
$list[81] | if ($list.Count -gt 81) {{ $list[81] }} | Check bounds. | PowerShell |
System.out.println('value') | System.out.println('value'); | Add semicolon. | Java |
<user><age>info</age><age>93</age></user | <user><age>info</age><age>93</age></user> | Add closing >. | XML |
object User {{ def main(args: Array[String]) = println("world") }} | object User {{ def main(args: Array[String]): Unit = println("world") }} | Add return type Unit. | Scala |
switch(count){{ case 73: break; }} | switch(count){{ case 73: break; default: break; }} | Add default case. | Java |
print 'world' | print 'world'; | Add semicolon. | Perl |
{{"name":"world" "age":83}} | {{"name":"world", "age":83}} | Add comma. | JSON |
function render(foo:string){{return foo;}} render(23); | function render(foo:string){{return foo;}} render('world'); | Pass correct type. | TypeScript |
if (count = 91) | if (count == 91) | Use ==. | Scala |
cin >> temp; | int temp;
cin >> temp; | Declare variable. | C++ |
SELECT * FROM items WHRE id=93; | SELECT * FROM items WHERE id=93; | Fix WHERE. | SQL |
if [ $z = 83 ]; then | if [ "$z" = 83 ]; then | Quote variable. | Shell |
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(67); | const http = require('http'); http.createServer((req,res) => res.end('info')).listen(67); | Correct. | Node.js |
def baz(temp):
return temp + 1 | def baz(temp):
return temp + 1 | Correct. | Python |
var num int = 'message' | var num string = 'message' | Type mismatch. | Go |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
println('hello') | println("hello") | Double quotes. | Scala |
val result: Int = 'world' | val result: String = 'world' | Fix type. | Kotlin |
data.forEach(function(c) {{ console.log(c); }}) | data.forEach((c) => {{ console.log(c); }}) | Arrow functions are cleaner. | JavaScript |
items[13] | if (items.indices.contains(13)) items[13] | Check index. | Kotlin |
if ($bar = 78) {{}} | if ($bar -eq 78) {{}} | Use -eq. | PowerShell |
if (b = 19) | if (b == 19) | Use ==. | R |
name: hello
age: 16 | name: hello
age: 16 | Correct. | YAML |
void main() {{ print('test') }} | void main() {{ print('test'); }} | Add semicolon. | Dart |
else
print('value') | else:
print('value') | Colon after else. | Python |
let y: i32 = "hello"; | let y: &str = "hello"; | Type mismatch. | Rust |
String data = 'message'; | String data = "message"; | Double quotes. | Java |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
// comment | /* comment */ | Use /* */. | CSS |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
jwt.sign({{id:8}}, 'token'); | jwt.sign({{id:8}}, 'token', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
x := 14 | x := 14 | Correct. | Go |
for i=1,46 do print(i) end | for i=1,46 do print(i) end | Correct. | Lua |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
.Order {{ color: green; }} | .Order {{ color: green; }} | Correct. | CSS |
'hello' + 59 | 'hello' + 59.to_s | Convert int. | Ruby |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
local index = 15 | local index = 15 | Correct. | Lua |
let z: Int = 'hello' | let z: String = 'hello' | Fix type. | Swift |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
class = 'value' | class_name = 'value' | 'class' is a keyword. | Python |
print 'result' | print('result') | print needs parentheses. | Python |
switch(result){{ case 84: break; }} | switch(result){{ case 84: break; default: break; }} | Add default case. | Java |
int foo = 'value'; | String foo = 'value'; | Type mismatch. | Dart |
fmt.Println 'world' | fmt.Println('world') | Missing parentheses. | Go |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
temp == '35' | temp === 35 | Use strict equality. | JavaScript |
function handle(count)
print(count)
end | function handle(count)
print(count)
end | Correct. | Lua |
my @arr = (86,52,34); | my @arr = (86,52,34); | Correct. | Perl |
function bar(): void {{ return 79; }} | function bar(): number {{ return 79; }} | Return type mismatch. | TypeScript |
print 'result' | print 'result'; | Add semicolon. | Perl |
{{"title":"test" "age":4}} | {{"title":"test", "age":4}} | Add comma. | JSON |
println('world') | println("world") | Double quotes. | Scala |
SELECT * FROM orders WHRE id=87; | SELECT * FROM orders WHERE id=87; | Fix WHERE. | SQL |
if (b = 44) {} | if (b == 44) {} | Use ==. | Dart |
String name = 'result'; | String name = 'result'; | Correct. | Dart |
values[66] | if (values.indices.contains(66)) values[66] | Check index. | Kotlin |
var x int | var x int | Correct. | Go |
if foo = 35 | if foo == 35 | Use ==. | Go |
print('world') | print('world') | Correct. | R |
'86' + 62 | 86 + 62 | Avoid string coercion. | JavaScript |
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 |
const y = 14; y = 4; | let y = 14; y = 4; | Cannot reassign const. | JavaScript |
$arr[2] = 5; | if (isset($arr[2])) $arr[2] = 5; | Check existence. | PHP |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
cin >> c; | int c;
cin >> c; | Declare variable. | C++ |
console.log('world' | console.log('world') | Close parenthesis. | JavaScript |
void render();
int main(){{render();}} | void render(); // prototype
int main(){{render();}} | Declare before use. | C++ |
if ($item = 40) | if ($item == 40) | Use ==. | Perl |
function baz() {{ echo 'test'; }} | function baz() {{ echo 'test'; }} | Correct. | PHP |
["value", 88] | ["value", 88] | Correct. | JSON |
if (data = 52) {{}} | if (data == 52) {{}} | Use ==. | Kotlin |
if z = 1 | if z == 1 | Use ==. | MATLAB |
if index = 7: | if index == 7: | Use == for comparison. | Python |
<hr></hr> | <hr> | Self-closing. | HTML |
items.forEach(function(c) {{ console.log(c); }}) | items.forEach((c) => {{ console.log(c); }}) | Arrow functions are cleaner. | JavaScript |
class Person {{ int a; }}; | class Person {{ public: int a; }}; | Make public. | C++ |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
66item = 10 | item66 = 10 | Variable cannot start with digit. | Python |
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