What is the best and effective way to read chars from string in java

Question

I want to know the effective way of reading a string which does not affect memory nor performance of the program.

I have the following implementation:

String x = "<BigBus><color>RED</color><number>123</number>........</BigBus>";
    char[] xh = new char[x.length()];
    for(int i=0;x.length();i+) {
       ch[i]=x.charAt(i);
       System.out.println(ch[i]);
    }

The sample string larger and have multiple lines.

Answer 1

The best solution will be to use Java 8 features for this.

Method chars() returns chars from given string. But it prints just char number value. For convenience we have to add utility method:

public class IterateString {

    private static void printChar(int aChar) {
        System.out.println((char) (aChar));
    }

    public static void main(String[] args) {
        String str = "<BigBus><color>RED</color><number>123</number>........</BigBus>";

        str.chars()
                .forEach(IterateString::printChar);

        // other options
        System.out.println();
        str.chars()
            .mapToObj(ch -> (char) ch)
            .forEach(System.out::println);

        System.out.println();
        str.chars()
            .filter(Character::isDigit)
            .forEach(IterateString::printChar);
    }
}

With streams you have a lot of benefits as lazy evaluation, lambda syntax, method references... For more info follow java 8 features.

BTW
your code snippet has some mistakes, it should look as follows:

    for (int i = 0; i < str.length(); i++) {
        ch[i] = str.charAt(i);
        System.out.println(ch[i]);
    }

instead of:

char[] xh = new char[x.length()];
for(int i=0; x.length(); i+) {
   ch[i] = x.charAt(i);
   System.out.println(ch[i]);
}