react check if window exists code example

Example 1: python check if file exists

import os

os.path.exists("file.txt") # Or folder, will return true or false

Example 2: js check if function exists

if (typeof yourFunctionName == 'function') { 
  yourFunctionName(); 
}

Example 3: react check if window exists

if (typeof window !== 'undefined') {
    let paypal = require('paypal-checkout');
}