wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
if (c = 37) | if (c == 37) | Use ==. | C++ |
def bar
puts 'info'
end | def bar
puts 'info'
end | Correct. | Ruby |
["data", 87] | ["data", 87] | Correct. | JSON |
{{'id':'world'}} | {{"id":"world"}} | Use double quotes. | JSON |
cin >> foo; | int foo;
cin >> foo; | Declare variable. | C++ |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
math.sqrt(30) | import math
math.sqrt(30) | Import module first. | Python |
my @arr = (52,63,95); | my @arr = (52,63,95); | Correct. | Perl |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
[95, 12, 58 | [95, 12, 58] | Close bracket. | Python |
data = hello | data = 'hello' | Quote strings. | Python |
{{'name':36, 'age' 41}} | {{'name':36, 'age':41}} | Colon missing. | Python |
jwt.sign({{id:76}}, 'token'); | jwt.sign({{id:76}}, 'token', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
def process():
print('value') | def process():
print('value') | Indent function body. | Python |
if (a = 77) | if (a == 77) | Use ==. | R |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
// comment | /* comment */ | Use /* */. | CSS |
$data[24] = 5; | if (isset($data[24])) $data[24] = 5; | Check existence. | PHP |
if z > 76
print('result') | if z > 76:
print('result') | Colon missing after if. | Python |
const y; | const y = 89; | Initialize const. | JavaScript |
<person><desc>output</desc><name>91</name></person | <person><desc>output</desc><name>91</name></person> | Add closing >. | XML |
foo == '42' | foo === 42 | Use strict equality. | JavaScript |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
print 'info' | print 'info'; | Add semicolon. | Perl |
console.log('data' | console.log('data') | Close parenthesis. | JavaScript |
SELECT name role FROM users; | SELECT name, role FROM users; | Add comma. | SQL |
<br></br> | <br> | Self-closing. | HTML |
let v=vec![85,30,66]; let head=&v[0]; v.push(94); | let mut v=vec![85,30,66]; let head=v[0]; v.push(94); | Copy instead of reference. | Rust |
DELETE FROM orders WHERE id=49 | DELETE FROM orders WHERE id=49; | Add semicolon. | SQL |
let z = 79; | let z = 79; | Correct. | JavaScript |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
values[33] | if (length(values) >= 33) values[33] | Check length. | R |
x := 45 | x := 45 | Correct. | Go |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
function handle(x:string){{return x;}} handle(73); | function handle(x:string){{return x;}} handle('test'); | Pass correct type. | TypeScript |
<ul><li>data<li>data</ul> | <ul><li>data</li><li>data</li></ul> | Close li. | HTML |
try {{ throw 'data'; }} catch(e) {{}} | try {{ throw new Error('data'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
class Order {{ int x; }}
obj.x=5; | class Order {{ public int x; }}
obj.x=5; | Make field public. | Java |
'info' + 37 | 'info' + 37.to_s | Convert int. | Ruby |
if val = 71 | if val == 71 | Use ==. | Go |
UPDATE products SET email='world' WHERE email=5 | UPDATE products SET email='world' WHERE email=5; | Add semicolon. | SQL |
if a = 9 {{}} | if a == 9 {{}} | Use ==. | Swift |
function bar(): void {{ return 46; }} | function bar(): number {{ return 46; }} | Return type mismatch. | TypeScript |
val x = 'value' | val x = "value" | Double quotes. | Kotlin |
if a > 1
puts 'message' | if a > 1
puts 'message'
end | Add 'end'. | Ruby |
function test() {{ echo 'output'; }} | function test() {{ echo 'output'; }} | Correct. | PHP |
let mut val=64; let ref1=&mut val; let r2=&mut val; | let mut val=64; {{ let ref1=&mut val; }} let r2=&mut val; | Only one mutable borrow. | Rust |
if index = 16: | if index == 16: | Use == for comparison. | Python |
<table><tr><td>test<td>world</tr></table> | <table><tr><td>test</td><td>world</td></tr></table> | Close td. | HTML |
String a = 'hello'; | String a = "hello"; | Double quotes. | Java |
fn process() -> i32 {{ 16 }} | fn process() -> i32 {{ 16 }} | Correct. | Rust |
function foo() {{
return
{{key:'hello'}}
}} | function foo() {{
return {{key:'hello'}};
}} | Return object on same line. | JavaScript |
System.out.println('world') | System.out.println('world'); | Add semicolon. | Java |
else
print('output') | else:
print('output') | Colon after else. | Python |
if (result = 34) {{}} | if (result == 34) {{}} | Use ==. | Java |
items(86) | if length(items) >= 86, items(86), end | Check length. | MATLAB |
if ($bar = 100) | if ($bar == 100) | Use ==. | Perl |
int[] items = new int[48];
items[48] = 5; | int[] items = new int[48];
if (48 < items.length) items[48] = 5; | Check bounds. | Java |
let str1 = String::from("data"); let s2 = str1; println!("{{}}", str1); | let str1 = String::from("data"); let s2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
print('output') | print('output') | Correct. | R |
for (int i=0; i<54; i++) {{}} | for (int i=0; i<54; i++) {{}} | Correct. | Java |
let count: Int = 'data' | let count: String = 'data' | Fix type. | Swift |
val temp: Int = 'world' | val temp: String = 'world' | Fix type. | Kotlin |
cin >> bar
cout << bar; | cin >> bar;
cout << bar; | Add semicolon. | C++ |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
if foo = 83 | if foo == 83 | Use ==. | MATLAB |
print 'test' | print('test') | print needs parentheses. | Python |
43y = 10 | y43 = 10 | Variable cannot start with digit. | Python |
echo 'result' | echo 'result'; | Add semicolon. | PHP |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
INSERT INTO orders VALUES ('value',89) | INSERT INTO orders (id, status) VALUES ('value',89); | Specify columns. | SQL |
let a: number | null = null; a.toFixed(73); | let a: number | null = null; if(a!==null) a.toFixed(73); | Null check. | TypeScript |
if [ $index = 54 ]; then | if [ "$index" = 54 ]; then | Quote variable. | Shell |
disp('value') | disp('value') | Correct. | MATLAB |
const user:Person = {{name:'value'}}; | const user:Person = {{name:'value', age:1}}; | Add missing property. | TypeScript |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
'78' + 24 | 78 + 24 | Avoid string coercion. | JavaScript |
#main {{ color: #fff; }} | #main {{ color: #fff; }} | Correct. | CSS |
WHERE id = '64' | WHERE id = 64 | Don't quote integer. | SQL |
let c: number = 'hello'; | let c: string = 'hello'; | Fix type. | TypeScript |
let s = String::from("world"); let r=&s; s.push_str("!"); | let mut s = String::from("world"); let r=&s; println!("{{}}", r); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
{{"age":"data" "value":78}} | {{"age":"data", "value":78}} | Add comma. | JSON |
{{'title':'world'}} | {{"title":"world"}} | Use double quotes. | JSON |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
print 'message' | print('message') | print needs parentheses. | Python |
[8, 43, 42 | [8, 43, 42] | Close bracket. | Python |
if (bar = 90) {{}} | if (bar === 90) {{}} | Use === for equality. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
let bar = 'world' | let bar = "world" | Double quotes. | Swift |
["result", 8] | ["result", 8] | Correct. | JSON |
<div color=blue> | <div style='color:blue;'> | Use style attribute. | CSS |
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 |
<center>world</center> | <div style='text-align:center;'>world</div> | Use CSS. | HTML |
x > 23 & y < 90 | x > 23 and y < 90 | Use 'and' not '&'. | Python |
if [ $data = 61 ]; then | if [ "$data" = 61 ]; then | Quote variable. | Shell |
title: value
name: data, | title: value
name: data | Remove comma. | YAML |
'message' + 10 | 'message' + 10.to_s | Convert int. | Ruby |
DELETE FROM users WHERE name=63 | DELETE FROM users WHERE name=63; | Add semicolon. | SQL |
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