How to get value of ON/OFF switch

I have On/Off switcher in my web project :

HTML:

<div  class="onoffswitch">
   <input type="checkbox" name="onoffswitch" class="onoffswitch-checkbox" 
    id="myonoffswitch" checked>
   <label class="onoffswitch-label" for="myonoffswitch">
     <span #onoffswitch class="onoffswitch-inner"></span>
     <span class="onoffswitch-switch"></span>
   </label>
</div>

CSS:

.onoffswitch-inner:before {
    content: "ON";
    padding-left: 10px;
    background-color: #93297E; color: #FFFFFF;
}

.onoffswitch-inner:after {
    content: "OFF";
    padding-right: 10px;
    background-color: #EEEEEE; color: #999999;
    text-align: right;
}

I want to know if the switcher is turned ON or OFF, I tried to get the value, using the next code, but it does not work:

getSwitcherValue(onoffswitch) {
   console.log("onoffswitch:"+onoffswitch.style.content);
}

Do you have any ideas how to get the value of on/off switcher?