how to give multiple classes in css selector code example

Example 1: css multiple classes

//HTML Code
<div class = 'firstClass secondClass'></div>

//CSS Code
.firstClass.secondClass {
  
}

Example 2: css change multiple classes

.objectOne, .objectTwo { /* We will now both be changed */
	margin: 0 auto; 
}

Example 3: css multiple classes

<div class="a-class another-class"></div>