swift字符串_04_字符串基本使用
//: Playground - noun: a place where people can play import UIKit //1.创建空字符串 var emptyStr1 = "" var emptyStr2 = String() //使用构造函数来创建空串 //判断字符串是否为空串 let isEmpty = emptyStr1.isEmpty //2.字符串的拼接 var name = "Kathy" let height = String("160") //(1)使用插值符号进行拼接 let fullString = "\(name)'s height is \(height)cm" //(2)运算符+重载 let fullString2 = name + "'s height is " + height + "cm" //(3)调用函数 name.appendContentsOf(fullString) //3.字符串的比较 let str1 = "We are 伐木累" let str2 = "We are 伐木累" //相等 if str1 == str2 { print("str == str2") } //是否包含前后缀 str1.hasPrefix("We are") str2.hasSuffix("kkk") //4.获取字符串中的字符 var loopStr = "I am a single 🐶" for char in loopStr.characters { print(char) } //5.获取字符串的长度 loopStr.characters.count //6.根据下标获取到某个字符 loopStr[loopStr.startIndex] //第一个字符 loopStr[loopStr.endIndex.predecessor()] //loopStr.endIndex:末尾的下一个的序号 loopStr[loopStr.endIndex.advancedBy(-5)] //7.插入删除 loopStr.insert("🌂", atIndex: loopStr.endIndex) loopStr.removeAtIndex(loopStr.endIndex.advancedBy(-4)) print(loopStr)
时光见证了成长,还很无知,我想一点点幼稚转为有知!