// test_string.ru

fn greet(name: &str) {   // &str rather than string type
  println!("Hello, {}!", name);
}

fn main()
{
  println!("test_string,ru running");
  let num = 123;
  println!("num= {:?}",num);
  let name = "me";
  println!("name= {:?}",name);
  println!(" ");

  println!("convert number to string");
  let n55 = 5.5;
  println!("n55= {:?}",n55);
  let s55 = n55.to_string();
  println!("s55= {:?}",s55);
  let n321 = 321;
  println!("n321= {:?}",n321);
  let s321 = n321.to_string();
  println!("s321= {:?}",s321);
  println!(" ");  

  println!("convert string to number");
  let s123 = "123";
  println!("s123= {:?}",s123);
  let n123 = s123.parse::<i32>().unwrap();
  println!("n123= {:?}",n123);
  let pi = "3.14159";
  println!("pi= {:?}",pi);
  let npi: f64 = pi.parse().unwrap();
  println!("npi= {:?}",npi);
  println!(" ");
  println!("&str default rathher than string type ");
  let first_name = "Pascal";
  let last_name = "Precht".to_string();
  greet(first_name);
  greet(&last_name); // `last_name` is passed by reference
  let company:&str="giant";
  let location:&str = "jonesvill";
  println!("company is {}  location at {}",company,location);
  println!(" ");
  let myst = "abcd".to_string();
  let part = &myst[1..3]; // like  for  gets [1] and [2]
  println!("myst= {}  part= {}",myst,part);
  let part2 = myst.get(1..3).unwrap();
  println!("myst= {}  part2= {}",myst,part2);
  println!(" ");
  let asrt = "abcdef";
  // Find cd substring in the string.
  let cd_index = asrt.find("cd").unwrap();
  println!("abcde cd index= {}",cd_index);
  println!(" ");
  println!("test_string,ru finished");
}