/**

5.4-函数的默认参数

*/

let str1 = joinString(s1: @H_403_39@"hell",toString: @H_403_39@"world")

print(str1)

let str2 = joinString(s1: @H_403_39@"hell",toString: @H_403_39@"world",joiner: @H_403_39@"¥")

print(str2)

let str3 = joinString2(s1: @H_403_39@"hellw",joiner: @H_403_39@"#")

print(str3)

let str4 = joinString2(s1: @H_403_39@"llll",toString: @H_403_39@"jijiji")

print(str4)