# Anything you write here runs in YOUR browser.
# Press Run (or Ctrl + Enter) and change something.
def two_sum(nums, target):
seen = {}
for i, n in enumerate(nums):
if target - n in seen:
return [seen[target - n], i]
seen[n] = i
return []
print(two_sum([2, 7, 11, 15], 9))
print(two_sum([3, 2, 4], 6))
Output
Press Run to see the output here. Whatever your program prints appears live.
Online JavaScript compiler - free, no sign up
Run JavaScript with real console output, in your browser. No account, no setup.
How to run JavaScript online
- 1. Pick JavaScript from the bar on the left.
- 2. Write your code, or load one of the examples.
- 3. Press Run, or Ctrl + Enter.
- 4. Need input? Put it in the Input tab, one value per line.
Why it is safe to use
- • Your code runs inside your own browser, never on our servers.
- • Network access is switched off in the sandbox that runs it.
- • Nothing is uploaded, stored or shared unless you copy the link yourself.
Questions people ask
- Is this JavaScript compiler free?
- Yes, and there is nothing to install or sign up for.
- Where does console.log go?
- Straight into the output panel beside your code, as it runs.
- Can I read input in JavaScript here?
- Yes - readline() returns the next line from the Input tab.