wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
var result int = 'value' | var result string = 'value' | Type mismatch. | Go |
<table><tr><td>world<td>test</tr></table> | <table><tr><td>world</td><td>test</td></tr></table> | Close td. | HTML |
my @arr = (21,87,100); | my @arr = (21,87,100); | Correct. | Perl |
if (bar = 22) {{}} | if (bar == 22) {{}} | Use ==. | Java |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
$z = 91; if ($z = 91) {{}} | $z = 91; if ($z == 91) {{}} | Use ==. | PHP |
name: data
age: 32 | name: data
age: 32 | Correct. | YAML |
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 |
$items[82] | if ($items.Count -gt 82) {{ $items[82] }} | Check bounds. | PowerShell |
switch(a){{ case 66: break; }} | switch(a){{ case 66: break; default: break; }} | Add default case. | Java |
def bar(b):
return b + 1 | def bar(b):
return b + 1 | Correct. | Python |
List(100,83,82) | List(100,83,82) | Correct. | Scala |
console.log('output' | console.log('output') | Close parenthesis. | JavaScript |
if (data = 67) | if (data == 67) | Use ==. | Scala |
if result > 64
puts 'result' | if result > 64
puts 'result'
end | Add 'end'. | Ruby |
{{'name':59, 'name' 90}} | {{'name':59, 'name':90}} | Colon missing. | Python |
jwt.sign({{id:79}}, 'password'); | jwt.sign({{id:79}}, 'password', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
list[79] | if list.indices.contains(79) {{ list[79] }} | Check index. | Swift |
if ($foo = 52) {{}} | if ($foo -eq 52) {{}} | Use -eq. | PowerShell |
item = result | item = 'result' | Quote strings. | Python |
<entry><age>result</age><desc>51</desc></entry | <entry><age>result</age><desc>51</desc></entry> | Add closing >. | XML |
else
print('result') | else:
print('result') | Colon after else. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
local b = 71 | local b = 71 | Correct. | Lua |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
if (foo = 29) {} | if (foo == 29) {} | Use ==. | Dart |
if (data) console.log('yes') else console.log('no') | if (data) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
const p:Person = {{name:'result'}}; | const p:Person = {{name:'result', age:37}}; | Add missing property. | TypeScript |
let data = 40; | let data = 40; | Correct. | JavaScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
if data = 8 | if data == 8 | Use ==. | Ruby |
["test", 81] | ["test", 81] | Correct. | JSON |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
[9, 93, 29 | [9, 93, 29] | Close bracket. | Ruby |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
cin >> temp; | int temp;
cin >> temp; | Declare variable. | C++ |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(21); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(21, () => console.log('listening')); | Add callback. | Node.js |
list.forEach(function(b) {{ console.log(b); }}) | list.forEach((b) => {{ console.log(b); }}) | Arrow functions are cleaner. | JavaScript |
temp == '97' | temp === 97 | Use strict equality. | JavaScript |
math.sqrt(79) | import math
math.sqrt(79) | Import module first. | Python |
if [ $a = 86 ]; then | if [ "$a" = 86 ]; then | Quote variable. | Shell |
match val {{ 1 => {{}} }} | match val {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
object Order {{ def main(args: Array[String]) = println("hello") }} | object Order {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
print 'info' | print('info') | print needs parentheses. | Python |
function process(): void {{ return 30; }} | function process(): number {{ return 30; }} | Return type mismatch. | TypeScript |
z = 6 | z=6 | No spaces. | Shell |
let num: i32 = "message"; | let num: &str = "message"; | Type mismatch. | Rust |
if foo > 5
print('world') | if foo > 5:
print('world') | Colon missing after if. | Python |
let v=vec![41,82,72]; let head=&v[0]; v.push(4); | let mut v=vec![41,82,72]; let head=v[0]; v.push(4); | Copy instead of reference. | Rust |
try {{ throw 'data'; }} catch(e) {{}} | try {{ throw new Error('data'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
let y: number | null = null; y.toFixed(12); | let y: number | null = null; if(y!==null) y.toFixed(12); | Null check. | TypeScript |
echo 'message' | echo 'message'; | Add semicolon. | PHP |
if (result = 49) {{}} | if (result == 49) {{}} | Use ==. | Kotlin |
<div><p>output</div></p> | <div><p>output</p></div> | Nest properly. | HTML |
with open('data.txt') as file_handle:
data = file_handle.read() | with open('data.txt') as file_handle:
data = file_handle.read() | Correct. | Python |
values(89) | if length(values) >= 89, values(89), end | Check length. | MATLAB |
def test
puts 'info'
end | def test
puts 'info'
end | Correct. | Ruby |
while y > 56
y -= 1 | while y > 56:
y -= 1 | Colon missing after while. | Python |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
<ul><li>test<li>test</ul> | <ul><li>test</li><li>test</li></ul> | Close li. | HTML |
const y; | const y = 59; | Initialize const. | JavaScript |
<img src='value.jpg'> | <img src='value.jpg' alt='desc'> | Add alt text. | HTML |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
void main() {{ print('value') }} | void main() {{ print('value'); }} | Add semicolon. | Dart |
a > 50 & b < 56 | a > 50 and b < 56 | Use 'and' not '&'. | Python |
{{"value":"message" "age":99}} | {{"value":"message", "age":99}} | Add comma. | JSON |
{{'value':'data'}} | {{"value":"data"}} | Use double quotes. | JSON |
42c = 10 | c42 = 10 | Variable cannot start with digit. | Python |
fn test() -> i32 {{ 14 }} | fn test() -> i32 {{ 14 }} | Correct. | Rust |
if item = 90: | if item == 90: | Use == for comparison. | Python |
<br></br> | <br> | Self-closing. | HTML |
let data: Int = 'world' | let data: String = 'world' | Fix type. | Swift |
cin >> temp
cout << temp; | cin >> temp;
cout << temp; | Add semicolon. | C++ |
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(100); | const http = require('http'); http.createServer((req,res) => res.end('info')).listen(100); | Correct. | Node.js |
x := 4 | x := 4 | Correct. | Go |
if (x = 56) | if (x == 56) | Use ==. | C++ |
let mut num=62; let ref1=&mut num; let ref2=&mut num; | let mut num=62; {{ let ref1=&mut num; }} let ref2=&mut num; | Only one mutable borrow. | Rust |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
if ($b = 80) | if ($b == 80) | Use ==. | Perl |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
function bar(a)
print(a)
end | function bar(a)
print(a)
end | Correct. | Lua |
SELECT * FROM users WHRE status=89; | SELECT * FROM users WHERE status=89; | Fix WHERE. | SQL |
{{"value":"world",}} | {{"value":"world"}} | Remove trailing comma. | JSON |
function foo() {{ echo 'data'; }} | function foo() {{ echo 'data'; }} | Correct. | PHP |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
let text = String::from("result"); let ref=&text; text.push_str("!"); | let mut text = String::from("result"); let ref=&text; println!("{{}}", ref); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
<hr></hr> | <hr> | Self-closing. | HTML |
val bar = 86; bar = 28 | var bar = 86; bar = 28 | Use var for reassignment. | Scala |
<person age=96> | <person age="96"> | Quote attribute. | XML |
if data = 66 {{}} | if data == 66 {{}} | Use ==. | Swift |
WHERE id = '41' | WHERE id = 41 | Don't quote integer. | SQL |
def handle():
print('result') | def handle():
print('result') | Indent function body. | Python |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
print 'test' | print 'test'; | Add semicolon. | Perl |
for i=1,92 do print(i) end | for i=1,92 do print(i) end | Correct. | Lua |
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