best method to iterate string in jajva code example

Example 1: java iterate over a string

String scientistName = "Isaac Newton";
 
for (int i = 0; i < scientistName.length(); i++) {
    System.out.print(scientistName.charAt(i) + " "); // I s a a c   N e w t o n
}

//*********************************************************
// you can cast a string into a char[]
String str = "strings are not primitive types!";
 

for (char ch : str.toCharArray()) {
    	System.out.print(scientistName.charAt(i) + " ");
    }
}

Example 2: iterate over string java

String str = "hello";
for (char c : str.toCharArray())
  //process c