爱学习~天天学习

摘要： 在字符串里插值var str = "hello"let i = 6var str2 = "hello \(i)"累加字符串var str = "hello"let i = 6var str+= "hello \(i)"用函数插入单个值字符var aaa = "fdasf"aaa.insert("c"... 阅读全文