generate random key in javascript code example

Example: generate random key in javascript

<h6>Content 1:</h6>
<textarea class="content1" name="content1" id= "content1" spellcheck="false" onclick="content1()" readonly></textarea>
<h6>Content 2:</h6>
<input type="text" class="content2" name="content2" id= "content2" spellcheck="false" onclick="content1()" readonly>


<script>
var random_generator1 = document.getElementById('content1') 
random_generator1.innerHTML = create_random_generator(10) 
var random_generator2 = document.getElementById('content2') 
random_generator2.innerHTML = create_random_generator(20) 
                                        
function create_random_generator(string_length){
    var random_string = ''
    var char = 'abcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ'
    var i
    
    for(i = 0; i < string_length; i++){
        random_string = random_string + char.charAt(Math.floor(Math.random()* char.length))
    }
    return random_string
}
</script>