1.截取前面三个字符串,要求输出结果为abc
let str ="abcdefghi"
let index = str.index(str.startIndex, offsetBy:3)//获取字符d的索引
let result = str.substring(to: index)//从起始截取到索引的所有字符串,即abc,注意不包含d
打印结果为 abc
2.截取第四个开始的所有字符串,要求输出结果为defghi
let str ="abcdefghi"
let index = str.index(str.startIndex, offsetBy:3)//获取字符d的索引
let result = str.substring(from: index)//从d的索引开始截取后面所有的字符串即defghi
打印结果为defghi
3.截取第4个开始的长度为2个字符串,要求结果输出为de
let str ="abcdefghi"
let startIndex = str.index(str.startIndex, offsetBy:3)//获取d的索引
let endIndex = str.index(startIndex, offsetBy:2)//从d的索引开始往后两个,即获取f的索引
let result = str.substring(with: startIndex..
打印结果为de
4.判断字符串是否包含某段字符
let str ="abcdefghi"
let result = str.contains("ac")
打印结果为false
let result = str.contains("abc")
打印结果为true
5.字符串大小写转换
let str ="ABCDEFGHI"
let result = str.lowercased()
输出结果为abcdefghi
let str ="abcdefghi"
let result = str.uppercased()
输出结果为ABCDEFGHI
6.指定字符串替换为其他字符串,将abc替换成m,使输出结果为mdefghi
let str ="abcdefghi"
let result = str.replacingOccurrences(of:"abc", with:"m")
输出结果为mdefghi
7.指定范围内的字符串替换为其他字符串,将cde替换成m,使输出结果为abmfghi
let str ="abcdefghi"
let startIndex = str.index(str.startIndex, offsetBy:2)
let endIndex = str.index(startIndex, offsetBy:3)
let result = str.replacingCharacters(in: startIndex..
输出结果为abmfghi
8.有时候不确定字符串的长度,需求为截取字符串末尾面开始往前5位,截取长度为2的字符串,使输出为ef
let str ="abcdefghi"
let startIndex = str.index(str.startIndex, offsetBy: str.lengthOfBytes(using: .utf8) -5)
let endIndex = str.index(startIndex, offsetBy:2)
let result = str.substring(with: startIndex..
输出结果为ef
9. 字符串转为数组,使得输出为["a", "b", "c", "d", "e", "f", "g", "h", "i"]
let str ="a.b.c.d.e.f.g.h.i"
let result = str.components(separatedBy:".")
输出为["a", "b", "c", "d", "e", "f", "g", "h", "I"]
10.Model数组格式化的时间字符串排序
self.appArr.sort(by: { (model1, model2) -> Bool in
return Int(model1.createTime!.dateStamp!) > Int(model2.createTime!.dateStamp!)
})
10.分割字符串
let str ="abcd,efghi"
let arrStr:[String] = str.components(separatedBy: ",")
print(arrStr)
