title: extract information from string using regex in R
body: <p>I have data like this i want to extract some information from x and y  </p>
  
  <pre><code>x= "{\"device_codename\": \"nikel\", \"brand\": \"Xiaomi\"}" 
  y= {"percent_incoming_nighttime": 0.88, "percent_outgoing_daytime": 9.29}
  </code></pre>
  
  <p>The result </p>
  
  <pre><code>device_codename   brand     percent_incoming_nighttime percent_outgoing_daytime
  nikel             Xiaomi    0.88                       9.29
  </code></pre>
  
  <p>I have tired using grep but iam getting errors any suggestion? </p>
  
  <pre><code>grep("device_codename", x, perl=TRUE, value=TRUE)
  </code></pre>