String案例演示

public class Application   {
    public static void main(String[] args) {
        String str="this is a text";
        //1 将str中的单词单独获取出来
        String[] s = str.split(" ");
        for (String a:
             s) {
            System.out.println(a);
        }
        /*
        this
        is
        a
        text
         */

        //2 将str中的text替换为practice
        System.out.println(str.replace("text","practice"));//this is a practice

        //3 在text前面插入一个easy
        System.out.println(str.replace("text","easy text"));//this is a easy text

        //4 将str中每个单词的首字母改为大写
        //System.out.println(str.replace("this is a text","This Is A Text"));//This Is A Text
        for (int i = 0; i <s.length ; i++) {
            //获取第一个字符
            char c = s[i].charAt(0);
            //将第一个字符改为大写
            char c1 = Character.toUpperCase(c);
            //在把每个单词拼接起来
            String s1 = c1 + s[i].substring(1);
            System.out.print(s1+" ");//This Is A Text
        }
    }
}