字符串和字符的值可以通過加法運(yùn)算符(+)相加在一起并創(chuàng)建一個(gè)新的字符串值:
let string1 = "hello"
let string2 = " there"
let character1: Character = "!"
let character2: Character = "?"
let stringPlusCharacter = string1 + character1 // 等于 "hello!"
let stringPlusString = string1 + string2 // 等于 "hello there"
let characterPlusString = character1 + string1 // 等于 "!hello"
let characterPlusCharacter = character1 + character2 // 等于 "!?"
您也可以通過加法賦值運(yùn)算符 (+=) 將一個(gè)字符串或者字符添加到一個(gè)已經(jīng)存在字符串變量上:
var instruction = "look over"
instruction += string2
// instruction 現(xiàn)在等于 "look over there"
var welcome = "good morning"
welcome += character1
// welcome 現(xiàn)在等于 "good morning!"
注意:
您不能將一個(gè)字符串或者字符添加到一個(gè)已經(jīng)存在的字符變量上,因?yàn)樽址兞恐荒馨粋€(gè)字符。