一、定义方法
1、通过字面
NSString * str = @"hello";
2、通过对象方法
NSString *str = [[NSString alloc] initWithUTF8String:"hello"]
3、通过类方法
NSString *str = [NSString stringWithFormat:@"%s":strs];
二、计算长度:
NSString * str = @"hello";
int len = [str length];
三、定义对象图:
#import <Foundation/Foundation.h>
#import "Student.h"
int main(int argc, const char * argv[])
{
@autoreleasepool {
Student *s = [Student new];
Student *ss = s;
ss->_name = @"tom";
NSLog(@"%@", s->_name);
}
return 0;
}