Besides for summing up numbers, the operator +
is also used for joining pieces of text (concatenation of two strings one after another). In programming, joining two pieces of text is called "concatenation". Here is how we can concatenate a text with a number by the +
operator:
var firstName = "Maria";
var lastName = "Ivanova";
var age = 19;
var str = firstName + " " + lastName + " @ " + age;
Console.WriteLine(str); // Maria Ivanova @ 19
Watch a video lesson about concatenating text and numbers: https://youtu.be/vPI-V2NG_CU.
Here is another example of concatenating text and numbers:
var a = 1.5;
var b = 2.5;
var sum = "The sum is: " + a + b;
Console.WriteLine(sum); // The sum is: 1.52.5
Did you notice something strange? Maybe you expected the numbers a
and b
to be summed? Actually, the concatenation works from right to left and the result above is absolutely correct. If we want to sum the numbers, we have to use brackets, in order to change the order of execution of the operations:
var a = 1.5;
var b = 2.5;
var sum = "The sum is: " + (a + b);
Console.WriteLine(sum); // The sum is: 4