可变字符串的创建
void
    // 预先分配10个字数的存储空间
    NSMutableString *str = [[NSMutableString alloc]  initWithCapacity:10];
    //  设置字符串内容
setString:@"1234"];
     
    //  拼接一个字符串
appendString:@"567"];
    //  拼接字符串
    [str appendFormat:@"age is %i and height is %.2f", 27,  1.55f];
     
    //  替换字符串
NSRange range = [str  rangeOfString:@"height"];
    //NSRange range = NSMakeRange(7, 3);
    [str replaceCharactersInRange:range withString:@"no"];
     
    //  插入字符串
    [str insertString:@"abc" atIndex:2];
     
    //  删除字符串
rangeOfString:@"age"];
    [str deleteCharactersInRange:range];
     
NSLog(@"%@", str);
     
    //  释放对象
release];
}
 
int main(int argc, const char
{
    @autoreleasepool {
        stringCreate();
    }
return 0;
}