IOS数组NSArray与NSMutableArray知识点

NSArray *array=[NSArray array];    //增加单个    //array=[NSArray arrayWithObject:@"wujy"];    //增加多个    array=[NSArray arrayWithObjects:@"VEVb",@".com",nil];    NSInteger arrayCount=array.count;    NSLog(@"当前array数组个数为：%ld",arrayCount);        int i=0;    for (id obj in array) {        NSLog(@"当前第%d个为%@",i,obj);        i++;    }        //常用的数组操作    NSString *lastString=[array lastObject];    NSLog(@"最后一个对象的值为：%@",lastString);        NSString *firstString=[array firstObject];    NSLog(@"第一个对象的值为：%@",firstString);        NSString *indexString=[array objectAtIndex:1];    NSLog(@"第二个对象的值为:%@",indexString);        NSInteger indexInt=[array indexOfObject:@"VEVb"];    NSLog(@"返回索引的位置：%ld",indexInt);        //将字符串转化成数组    NSString *arrayString=@"a,b,c,d";    NSArray *newArray=[arrayString componentsSeparatedByString:@","];    for (id obj in newArray) {        NSLog(@"当前字符串转化为%@",obj);    }        //判断数组是否存在元素    if ([newArray containsObject:@"c"]) {        NSLog(@"存在字母c的元素");    }    else    {        NSLog(@"不存在字母c的元素");    }        //简便创建    NSArray *twoArray=[NSArray arrayWithObjects:@1,@2,@3,@4,@5,nil];    //迭代器遍历  reverSEObjectEnumerator数组元素从后向前访问    NSEnumerator *arrayenumerator=[twoArray reverseObjectEnumerator];    id obj=nil;    while (obj=[arrayenumerator nextObject]) {        NSLog(@"当前值为：%d",[obj intValue]);    }                    //利用BlocksKit插件进行遍历    NSArray *frArray=[NSArray arrayWithObjects:@(0.2),@(0.5),@(0.9),nil];    [frArray bk_each:^(id obj) {        NSLog(@"%@",obj);    }];        //跟数组项进行对比，若不存在则为空 存在则为符合的值    id found=[frArray bk_match:^BOOL(id obj) {        BOOL match=([obj floatValue]==0.5)?YES:NO;        return match;    }];    NSLog(@"有符合的值：%@",found);        id notFound=[frArray bk_match:^BOOL(id obj) {        BOOL match=([obj floatValue]==0.7)?YES:NO;        return match;    }];    NSLog(@"没有符合的值（nil）：%@",notFound);    //过滤数组    NSArray *selectFound=[frArray bk_select:^BOOL(id obj) {        BOOL match=([obj floatValue]>0.3)?YES:NO;        return match;    }];    NSLog(@"当前过滤array数组个数为：%ld",selectFound.count);    for (id obj in selectFound) {        NSLog(@"当前符合为%@",obj);    }        //过滤数组 取相反    NSArray *rejectFound=[frArray bk_reject:^BOOL(id obj) {        BOOL match=([obj floatValue]>0.3)?YES:NO;        return match;    }];    NSLog(@"当前取反array数组个数为：%ld",rejectFound.count);    for (id obj in rejectFound) {        NSLog(@"当前符合为（0.2符合）%@",obj);    }        //遍历数组 对每个值都进行修改 组成新的数组    NSArray *mapFound = [array bk_map:^id(id obj) {        return [obj stringByAppendingString:@".png"];    }];    for (id obj in mapFound) {        NSLog(@"当前map %@",obj);    }        //合并数组的各项值    //进行数组的合并 中间可以加分格符之类 (这边是前面加的一个|;合并后的字符串为：|VEVb.com)    NSString *concentrated = [array bk_reduce:@"|" withBlock:^id(id sum, id obj) {        return [sum stringByAppendingString:obj];    }];    NSLog(@"合并后的字符串为:%@",concentrated);        //相加  还有一个为整数型 bk_reduceInteger    float value = [frArray bk_reduceFloat:0 withBlock:^CGFloat(CGFloat result, id obj) {        return result + [obj floatValue];    }];    NSLog(@“合并后的frArray值为：%f",value);

//从array转nsmutablearray    NSArray *array=[[NSArray alloc] initWithObjects:@"wujy",@"VEVb",nil];    NSMutableArray *mutableArray=[NSMutableArray arrayWithArray:array];        //创建NSMutableArray    NSMutableArray *newMutableArray=[NSMutableArray array];    [newMutableArray addObject:@"a"];    [newMutableArray addObjectsFromArray:[[NSArray alloc] initWithObjects:@"b",@"c",@"d",@"e",nil]];    //迭代器遍历  reverseObjectEnumerator数组元素从后向前访问    NSEnumerator *arrayenumerator=[newMutableArray reverseObjectEnumerator];    id obj=nil;    while (obj=[arrayenumerator nextObject]) {        NSLog(@"当前值为：%@",obj);    }        //创建NSMutableArray    NSMutableArray *capacityArray=[[NSMutableArray alloc] initWithCapacity:5];    [capacityArray addObjectsFromArray:[[NSArray alloc] initWithObjects:@1,@2,@3,nil]];    NSLog(@"删除前(1,2,3):%@",capacityArray);    //删除指定的元素    [capacityArray removeObject:@3];    NSLog(@"删除后(1,2):%@",capacityArray);    //插入    [capacityArray insertObject:@4 atIndex:2];    NSLog(@"插入后的(1,2,4)%@",capacityArray);    //插入多个    NSIndexSet *set=[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(0, 2)];    [capacityArray insertObjects:[[NSArray alloc] initWithObjects:@5,@6,nil] atIndexes:set];    NSLog(@"插入多个以后的(5,6,1,2,4):%@",capacityArray);        //Blocks操作    //过滤    [capacityArray bk_performSelect:^BOOL(id obj) {        BOOL match=([obj intValue]>2)?YES:NO;        return match;    }];    NSLog(@"过滤后的数组值为(5,6,4)：%@",capacityArray);        //取反过滤    [capacityArray bk_performReject:^BOOL(id obj) {        BOOL match=([obj intValue]>5)?YES:NO;        return match;    }];    NSLog(@"过滤取反后的数组值为(5,4)：%@",capacityArray);        //对数组的值进行操作    [capacityArray bk_performMap:^id(id obj) {        return [NSNumber numberWithInt:[obj intValue]+1];    }];    NSLog(@"map后的数组值为(6,5)：%@",capacityArray);