title: react className conditional setting according to all of state
body: <p>I currently making a vocabulary website and got state from mysql, and the state is like this.</p>
  <pre><code>1: memorize : 0
  2: memorize : 0
  3: memorize : 0
  4: memorize : 0
  5: memorize : 1
  6: memorize : 0
  </code></pre>
  <p>So if I check the checkbox on the list of website, each state turns  to 1. and 0 means not checked. every time check the box, it changes the value of state(from0 to 1)</p>
  <p>and what I want to make is the button(finish) that active&amp;disable. If all of the state turn in to 1, I want to make this finish button active.
  So I decided to make 2 className, active, notActive, however it is really hard to make the condition.</p>
  <p>How to use &quot;If&quot; structure to examine all state? I have tried using State.map, but this only works when examine each state, not whole.</p>
  <p>in conclusion, I want to make</p>
  <pre><code>  useEffect(() =&gt;{if( all of the state === 1){ buttonClassName = active}}
  </code></pre>
  <p>could you tell me how to embody&quot;all of the state&quot; ?</p>