Talking about the common methods of Swift's string

Below, let's enumerate some of the commonly used swift string methods

First, let's define some string variables and constants.

" Hello World " // The value is Hello you string " Hai " "! "

String connection, in fact, the string of connection words, directly with var i:string = "abc" + "Def" can be done, incredibly we talk about the method of string,

Let's try it with append.

// The value is Hello world! // appendcontentsof () is the connection of a string welcome.appendcontentsof ("CCC"//  The value is Hello world! C c c

Turn the first letter into uppercase

// The value is Hello world

Displays the length of the string

Str1.endindex//value is one//     value of one

We'll define a string again.

var a:string =  "asdf"

The first subscript of a string

A.startindex

Inserts a character in the first item of a string

" C " ,  atindex:a.startindex)    //casdf

Displays the first character of a string

Here, it is necessary to explain, here the brackets are not allowed to fill in the numbers, a[0] is wrong, A[a.startindex] is correct, pay attention!!

Get the next character. Successor () and the previous character. predecessor ()

/ Get the next character. Successor () A[a.startindex.successor ()]    //a//  Gets the last character. predecessor ()A[a.startindex.successor (). predecessor ()]  //C

If you want to get a value from a string, you can add a Advancedby () on top of it.

A[a.startindex.advancedby (2)]  //s

Intercepts a string that specifies the subscript to the last character

A.substringfromindex (A.startindex.advancedby (2))  //s D F

Intercepts a string that specifies the subscript to the first character

A.substringtoindex (A.startindex.advancedby (3))  //cas

Determines whether the first character is a character, and returns a true if correct

A.hasprefix ("C")  //true

Determines whether the last character is a character, and returns a true if correct

A.hassuffix ("F")  //true

To cut a string into an array of strings by specifying a character

A.componentsseparatedbystring ("a")  //["C", "SDF"]

Well, that's the way we use strings,

Talking about the common methods of Swift's string