Containing variable string concatenation (string.Format () or $ "")

 

Containing variable strings together, not generally used to connect the + strings, using the following two ways:

 

一、string.Format()

Second, the $ "" (available in more than six versions of C #, recommended such an approach)

. 1          public List <the Person> FindListByLastName ( String lastName)
 2          {
 . 3              the using (DB = the IDbConnection new new the SqlConnection (DbHelper.ConnectionString))
 . 4              {
 . 5                  // Method one: Use string.Format (), write a string placeholder { 0}, followed by a variable 
. 6                  String SQL = String .Format ( " the SELECT * the FROM the Person the WHERE the lastName = '{0}' " , lastName);
 . 7  
. 8                  // two: $ "", directly write variables in {} 
. 9                  String SQL = $ " the SELECT * the FROM the Person the WHERE the lastName = '{lastName}' ";
10 
11                 IEnumerable<Person> list = db.Query<Person>(sql);
12                 return list.ToList();
13             }
14         }