//初始化
//iniWithString------Returns an NSString object initialized by copying the characters from another given string.
// 返回一个NSString对象初始化复制来自另一个给定字符串的字符。
NSString *str = @"liuyafang";
NSString *str1 = [[NSString alloc] initWithString:str];
NSLog(@"str1 = %@", str1);
//计算字符串长度
//length------Returns the number of Unicode characters in the receiver.
//返回接收器中Unicode字符的数量
NSInteger count = [str length]; //可见长度
NSLog( @"%ld", count);
//initWithFormat:
//Returns an NSString object initialized by using a given format string as a template into which the remaining argument values are substituted.
//返回一个NSString对象初始化使用给定的格式字符串作为模板,其余参数值代替。
NSString *str2 = @"dapingmu";
NSString *str3 = [[NSString alloc] initWithFormat:@"liuyafang"];
NSLog(@"str2 = %@", str2);
NSLog(@"str3 = %@", str3);
//判断是否以指定字符开头或者结尾
BOOL pre = [str3 hasPrefix:@"liu"];
NSLog(@"%d", pre);
BOOL suf = [str3 hasSuffix:@"fang"];
NSLog(@"%d", suf);
//截取字符串的长度和起始位置－－－－Finds and returns the range of the first occurrence of a given string within the receiver.
//
NSRange rag =[str3 rangeOfString:@"liu"];
NSLog(@"length = %ld, lacation = %ld", rag.length, rag.location);
//截取从输入的起始位置开始输出
NSString *sub = [str3 substringFromIndex:3];
NSLog(@"%@", sub);
//截取到输入的位置并输出
NSString *subb = [str3 substringToIndex:3];
NSLog(@"%@", subb);
//截取一个范围字符串
NSRange aa = {0 , 4};
NSString *ran1 = [str3 substringWithRange:aa];
NSString *ran = [str3 substringWithRange:NSMakeRange(0, 5)]; //NSMakeRange(0, 5) 范围的起始位置和末尾位置
NSLog(@"%@", ran1);
NSLog(@"%@", ran);
//拼接字符串
NSString *str4 = @" very good !";
NSString *app = [str stringByAppendingString:str4];
NSLog(@"%@", app);
NSLog(@"%@",str);
NSString *b = [str stringByAppendingFormat:@"%@==%d", str,5]; //格式化拼接，，，有问题 ，，
NSLog(@"%@",b);
//替换字符串
NSString *rep = [str3 stringByReplacingOccurrencesOfString:@"ya" withString:@"xiao"];
NSLog(@"%@", rep);
//转换成小写的
NSString *lowe= [@"ljlkmJNnhjnHhhbhHnbjjbnghUKJkj" lowercaseString];
NSLog(@"%@", lowe);
//首字母转换成大写；
NSString *cap = [@"ad Hj da ajda ajdl la " capitalizedString];
NSLog(@"%@",cap);
NSMutableString *mutabal = [NSMutableString stringWithCapacity:5];
NSLog(@"%@", mutabal);
NSMutableString *mutabal1 =[NSMutableString stringWithFormat:@"liuyafang"];
NSLog(@"%@", mutabal1);
//可变字符串拼接
//Adds a constructed string to the receiver.---添加一个构造字符串到接收方。
[mutabal1 appendFormat:@"good"];
NSLog(@"%@", mutabal1);
[mutabal1 appendFormat:@"%@", @"good"];
NSLog(@"%@", mutabal1);
//Adds to the end of the receiver the characters of a given string.--增加了接收机的最后一个给定字符串的字符。
[mutabal1 appendString:@"what!"];
NSLog(@"%@", mutabal1);
[mutabal1 stringByAppendingString:@"nimei"];
NSLog(@"----------%@", mutabal1);
//删除范围字符串
// Removes from the receiver the characters in a given range.----删除来自接收者的角色在一个给定的范围内。
NSRange aaa = {0, 3};
[mutabal1 deleteCharactersInRange:aaa];
NSLog(@"%@", mutabal1);
//NSMakeRange-------Creates a new NSRange from the specified values.--创建一个新的NSRange指定值。
[mutabal1 deleteCharactersInRange:NSMakeRange(0, 3)];
NSLog(@"%@",mutabal1);
//Replaces the characters of the receiver with those in a given string.----替换字符的接收器与给定的字符串。
[mutabal1 setString:@"liu"];
NSLog(@"%@", mutabal1);
//作业1。。判断是否以EfGk结尾，如果是替换成WXYZ，然后转变成小写
NSString *exercise = @"aBcD_EfGk";
BOOL a1 = [exercise hasSuffix:@"EfGk"];
NSLog(@"%d", a1);
NSString *exer = [exercise stringByReplacingOccurrencesOfString:@"EfGk" withString:@"WXYZ"];
NSLog(@"---====>%@", exer);
NSString *exer1 = [exer lowercaseString];
NSLog(@"------>%@",exer1);
//作业1。2判断是都以png结尾，如果是替换成jpg，如果不是则添加.jpg
NSMutableString *page = [NSMutableString stringWithFormat:@"xiaoliu.png"];
BOOL aa11 = [page hasSuffix:@"png"];
NSLog(@"%d",aa11);
if ( aa11 == 1) {
NSString *page1 = [page stringByReplacingOccurrencesOfString:@"png" withString:@"jpg"];
NSLog(@"%@", page1);
}else{
[page appendString:@".jpg"];
NSLog(@"%@", page);
}
//数组初始化，，获取元素个数
NSArray *arr = [NSArray arrayWithObjects:@"ss",@"dd",@"aa", nil];
NSLog(@"%@", arr);
NSInteger con = [arr count];
NSLog(@"%ld", con);
// 根据对象获得所引致
//Returns the lowest index whose corresponding array value is equal to a given object.---
NSInteger dd = [arr indexOfObject:@"dd"];
NSLog(@"%ld", dd);
//根据所引致获得对象
//Returns the object located at the specified index.
NSArray *ppp = [arr objectAtIndex:0];
NSLog(@"0000000%@", ppp);
///-------------可变数组--------------///
NSMutableArray *mutarr = [NSMutableArray arrayWithCapacity:5];
NSLog(@"%@", mutarr);
NSMutableArray *mt = [NSMutableArray arrayWithObjects:@"aaa", @"bbb", @"ccc", @"ddd", nil];
NSMutableArray *mm = [NSMutableArray arrayWithObjects:@"ee", @"qq", nil];
NSLog(@"%@", mt);
//添加元素
//Inserts a given object at the end of the array.
[mt addObject:@"fff"];
NSLog(@"%@", mt);
//插入元素
// Inserts a given object into the array's contents at a given index.
[mt insertObject:@"ooo" atIndex:2];
NSLog(@"%@", mt);
//数组连接，，，
//Adds the objects contained in another given array to the end of the receiving array’s content.
[mt addObjectsFromArray:mm];
NSLog(@"%@", mt);
//删除元素
[mt removeObjectAtIndex:2];
NSLog(@"%@", mt);
//替换元素
[mt replaceObjectAtIndex:0 withObject:@"ttttt"];
NSLog(@"%@", mt);
//交换两个指定位置对元素
[mt exchangeObjectAtIndex:0 withObjectAtIndex:1];
NSLog(@"%@", mt);
//图书管理
// NSMutableArray *library = [NSMutableArray arrayWithObjects:@"tushu1",@"tushu2", @"tushu3", @"tushu4", nil];
// NSInteger count1 = [library count];
// NSInteger ddd;
// NSLog(@"1-添加图书2-删除图书3-修改图书4-查找图书5-查看图书");
// scanf("%ld", &ddd);
// if (ddd == 1) {
// [library addObject:@"tushu5"];
// NSLog(@"%@", library);
// }
// if (ddd == 2) {
// [library removeObject:@"tushu3"];
// NSLog(@"%@", library);
// }
// if (ddd == 3) {
// [library setObject:@"tushu0" atIndexedSubscript:0];
// NSLog(@"%@", library);
// }
// if (ddd == 4) {
// NSInteger place = [library indexOfObject:@"tushu3"];
// NSLog(@"%ld", place);
// }
// if (ddd == 5) {
// for (int i = 0; i < count1; i++) {
// NSLog(@"%@",library[i]);
// }
// }
//正式作业1；
NSString *jiequ = @"20|http://www.baidu.com";
NSString *neww = [jiequ substringFromIndex:3]; //从这个位置开始截取， 截取前面输出后面。
NSLog(@"%@", neww);
NSString *new = [jiequ substringToIndex:2]; //截取到这个位置
NSLog(@"%@", new);
//将文件改写成213
NSString *qing = @"文艺青年";
NSString *a213 = [qing stringByReplacingOccurrencesOfString:@"文艺" withString:@"213"];
NSLog(@"%@", a213);
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