Objective-C基础笔记（8)Foundation常用类NSString

一、创建字符串的方法

void stringCreate(){
    //方法1
    NSString *str1 = @"A String!";
    //方法2
    NSString *str2 = [[[NSString alloc] init] autorelease];
    str2 = @"A String!";
    [str2 release];
    //方法3
    NSString *str3 = [[NSString alloc] initWithString:@"A String!"];
    [str3 release];
    //释放内存后 str3指向新内存
    str3 = [NSString stringWithString:@"A String!"];
    //方法4
    NSString *str4 = [[NSString alloc] initWithUTF8String:"A String!"];
    [str4 release];
    //方法5
    NSString *str5 = [[NSString alloc] initWithFormat:@"My age is %i and height is %.2f", 19, 1.55f];
    [str5 release];
    //str5指向新内存
    str5 = [NSString stringWithFormat:@"My age is %i and height is %.2", 19, 1.55f];
}void stringCreate(){
    //方法1