JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<style>
	pre { margin: 0; width: 250px; }
	i,b { display: block; height: 50px; width: 50px; float: left; }
	b { background: red; } 
</style>
<pre>
<script>
	var m = [];
	var i = 0;
	while(i<5){
		var j = 0;
		m[i] = [];
		while(j<5){
			m[i][j] = Math.round(Math.random());
			if(m[i][j]){
				document.write('<b></b>');
			} else {
				document.write('<i></i>');
			}
			j++;
		}
		i++;
	}
</script>
</pre>
<script>

    function ClearObjects(x, y){
        if (x < 0 || y < 0 || x >= m.length || y >= m[x].length) return false;
        if (m[x][y] == 1){
            m[x][y] = 0;
            ClearObjects(x - 1, y);
            ClearObjects(x + 1, y);
            ClearObjects(x, y - 1);
            ClearObjects(x, y + 1);
            return true;
        }
        return false;
    }
	
	var objects = 0;
        for (var i = 0; i < m.length; i++)
            for (var j = 0; j < m[i].length; j++)
                if (ClearObjects(i, j))
                    objects++;
	
	document.write(objects);
	
</script>