rust

rust.rs

// use std::fmt;
fn main() {
	let name = format!("shiv shankar");
	let new_name :String ;
	println!("actual name = {:?}",name );

	//	shadow of name with mut
	let (mut name, title_name) = title_case(name);

	{
		// passing &mut data tmp block access of varible
		// remove new scope and see magic
		let r = &mut name;
		new_name = change_name(r);
		
		// let r2 = &mut name; // panic! only one &mut ref allow at once
	}

	println!("new socpe name = {:?}",name );
	println!("title name = {:?}",title_name );
	println!("new name = {:?}",new_name );

}

fn change_name(name:&mut String) -> String {
	let mut new_name = name.clone();
	
	// new_name =new_name[1..].to_string().push('!');
	// println!("{:?}	",new_name );
	
	
	//	change actual name
	name.push_str(" sharma");
	
	//	return new_name
	new_name
}

fn title_case(name:String) -> (String, String) {
	let mut title_name = String::new();
	for word in name.split(" ") {
		title_name.push_str(&word.to_uppercase());
		//	 notice " " is string while ' ' is space char
 		title_name.push(' ');
	}
	(name, title_name)
}