wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if (index = 69) {{}} | if (index == 69) {{}} | Use ==. | Kotlin |
if (b = 71) | if (b == 71) | Use ==. | C++ |
<div><p>hello</div></p> | <div><p>hello</p></div> | Nest properly. | HTML |
print 'world' | print('world') | print needs parentheses. | Python |
// comment | /* comment */ | Use /* */. | CSS |
const user:Person = {{name:'result'}}; | const user:Person = {{name:'result', age:89}}; | Add missing property. | TypeScript |
if [ $a = 67 ]; then | if [ "$a" = 67 ]; then | Quote variable. | Shell |
def foo(x):
return x + 1 | def foo(x):
return x + 1 | Correct. | Python |
const http = require('http'); http.createServer((req,res) => res.end('data')).listen(96); | const http = require('http'); http.createServer((req,res) => res.end('data')).listen(96); | Correct. | Node.js |
if (b) console.log('yes') else console.log('no') | if (b) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
arr(89) | if length(arr) >= 89, arr(89), end | Check length. | MATLAB |
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
fmt.Println 'result' | fmt.Println('result') | Missing parentheses. | Go |
for a in range(86)
print(a) | for a in range(86):
print(a) | Colon after for. | Python |
count == '83' | count === 83 | Use strict equality. | JavaScript |
def handle():
print('message') | def handle():
print('message') | Indent function body. | Python |
<hr></hr> | <hr> | Self-closing. | HTML |
var x int | var x int | Correct. | Go |
int val = 'world'; | String val = 'world'; | Type mismatch. | Dart |
x := 87 | x := 87 | Correct. | Go |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
{{'title':'info'}} | {{"title":"info"}} | Use double quotes. | JSON |
#footer {{ color: blue; }} | #footer {{ color: blue; }} | Correct. | CSS |
JOIN products ON items.id = products.age | JOIN products ON items.id = products.age | Correct. | SQL |
let str1 = String::from("info"); let str2 = str1; println!("{{}}", str1); | let str1 = String::from("info"); let str2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
let index: number = 'test'; | let index: string = 'test'; | Fix type. | TypeScript |
y > 19 & a < 13 | y > 19 and a < 13 | Use 'and' not '&'. | Python |
cin >> num
cout << num; | cin >> num;
cout << num; | Add semicolon. | C++ |
class Order {{ int data; }}
obj.data=5; | class Order {{ public int data; }}
obj.data=5; | Make field public. | Java |
int items[99]; items[99]=5; | int items[99]; if(99<99){{}} else items[99]=5; | Bounds check. | C++ |
if c = 71 | if c == 71 | Use ==. | Go |
let count = 'message' | let count = "message" | Double quotes. | Swift |
if c > 90
puts 'world' | if c > 90
puts 'world'
end | Add 'end'. | Ruby |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
let result: Int = 'result' | let result: String = 'result' | Fix type. | Swift |
<ul><li>world<li>world</ul> | <ul><li>world</li><li>world</li></ul> | Close li. | HTML |
List(33,1,84) | List(33,1,84) | Correct. | Scala |
list[45] | if (length(list) >= 45) list[45] | Check length. | R |
let b: i32 = "test"; | let b: &str = "test"; | Type mismatch. | Rust |
with open('data.txt') as fh:
data = fh.read() | with open('data.txt') as fh:
data = fh.read() | Correct. | Python |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
if (b = 73) | if (b == 73) | Use ==. | R |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
let vec=vec![21,77,19]; let head=&vec[0]; vec.push(79); | let mut vec=vec![21,77,19]; let head=vec[0]; vec.push(79); | Copy instead of reference. | Rust |
function baz(z)
print(z)
end | function baz(z)
print(z)
end | Correct. | Lua |
'84' + 72 | 84 + 72 | Avoid string coercion. | JavaScript |
.Order {{ color: green; }} | .Order {{ color: green; }} | Correct. | CSS |
<ul><li>data<li>hello</ul> | <ul><li>data</li><li>hello</li></ul> | Close li. | HTML |
let s = String::from("data"); let ref=&s; s.push_str("!"); | let mut s = String::from("data"); let ref=&s; println!("{{}}", ref); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
class User {{ int b; }}
obj.b=5; | class User {{ public int b; }}
obj.b=5; | Make field public. | Java |
if (b = 60) {{}} | if (b == 60) {{}} | Use ==. | Java |
let str1 = String::from("test"); let text2 = str1; println!("{{}}", str1); | let str1 = String::from("test"); let text2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
<img src='hello.jpg'> | <img src='hello.jpg' alt='desc'> | Add alt text. | HTML |
def bar(temp):
return temp + 1 | def bar(temp):
return temp + 1 | Correct. | Python |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
items.forEach(function(c) {{ console.log(c); }}) | items.forEach((c) => {{ console.log(c); }}) | Arrow functions are cleaner. | JavaScript |
def bar():
print('value') | def bar():
print('value') | Indent function body. | Python |
x := 42 | x := 42 | Correct. | Go |
'output' + 73 | 'output' + str(73) | Can't add int to string. | Python |
yield b | yield b | Correct yield. | Python |
fmt.Println 'hello' | fmt.Println('hello') | Missing parentheses. | Go |
[83, 87, 68 | [83, 87, 68] | Close bracket. | Python |
def process
puts 'value'
end | def process
puts 'value'
end | Correct. | Ruby |
if index = 23 | if index == 23 | Use ==. | Go |
if a = 37 {{}} | if a == 37 {{}} | Use ==. | Swift |
SELECT age email FROM users; | SELECT age, email FROM users; | Add comma. | SQL |
void main() {{ print('test') }} | void main() {{ print('test'); }} | Add semicolon. | Dart |
WHERE name = '12' | WHERE name = 12 | Don't quote integer. | SQL |
if index > 16
print('hello') | if index > 16:
print('hello') | Colon missing after if. | Python |
if a = 56 then
print('info')
end | if a == 56 then
print('info')
end | Use ==. | Lua |
System.out.println('test') | System.out.println('test'); | Add semicolon. | Java |
while c > 94
c -= 1 | while c > 94:
c -= 1 | Colon missing after while. | Python |
<person age=25> | <person age="25"> | Quote attribute. | XML |
if [ $count = 39 ]; then | if [ "$count" = 39 ]; then | Quote variable. | Shell |
if (val = 30) {{}} | if (val == 30) {{}} | Use ==. | Kotlin |
with open('input.csv') as fh:
data = fh.read() | with open('input.csv') as fh:
data = fh.read() | Correct. | Python |
<entry name='result'/> | <entry name="result"/> | Double quotes. | XML |
let val: number = 'value'; | let val: string = 'value'; | Fix type. | TypeScript |
class Person {{ int bar; }}; | class Person {{ public: int bar; }}; | Make public. | C++ |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
{ "name": "value" } | { "name": "value" } | Correct. | JSON |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
function bar() {{
return
{{key:'data'}}
}} | function bar() {{
return {{key:'data'}};
}} | Return object on same line. | JavaScript |
println('test') | println("test") | Double quotes. | Scala |
{{'name':8, 'age' 9}} | {{'name':8, 'age':9}} | Colon missing. | Python |
for (int i=0; i<42; i++) {{}} | for (int i=0; i<42; i++) {{}} | Correct. | Java |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
List(69,80,92) | List(69,80,92) | Correct. | Scala |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
json.sqrt(47) | import json
json.sqrt(47) | Import module first. | Python |
let mut item=49; let ref1=&mut item; let r2=&mut item; | let mut item=49; {{ let ref1=&mut item; }} let r2=&mut item; | Only one mutable borrow. | Rust |
if (bar = 22) {} | if (bar == 22) {} | Use ==. | Dart |
if ($data = 76) | if ($data == 76) | Use ==. | Perl |
local num = 25 | local num = 25 | Correct. | Lua |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
switch(data){{ case 57: break; }} | switch(data){{ case 57: break; default: break; }} | Add default case. | Java |
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