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黑马程序员--NSArray遍历

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NSArray *array = [NSArray arrayWithObjects: @“1”,@“2”,@“3”,nil];

//array[i] = [array objectAtIndex:i]


一.  for循环


int count = array.count;//减少调用次数

for( int i=0; i<count; i++){

    NSLog(@"%i-%@", i, array[i]);

}

二.  增强for

for(id obj in array){

    NSLog(@"%@",elm);

}

三.  迭代器


NSEnumerator *enumerator = [array objectEnumerator];

NSArray *obj = nil;

while(obj = [enumerator nextObject]){

    NSLog(@"obj=%@",obj);

}


四.  Block块遍历


[array enumeratorObjectsUsingBlock:

^(NSArray *obj, NSUInteger idx, BOOL  *stop){

    NSLog(@"%i-%@",idx,elm);

    //若终断循环

    //*stop = YES;

}];


比如:


内容只是重要的代码块,需要实现请将各代码块放在main函数中去运行


NSArray *arr = @[@1,@2,@3,@4,@6];


NSMutableArray *array = [NSMutableArray arrayWithArray:arr];

NSNumber *value = http://www.mamicode.com/@5;


//现在要将@5插入,使array内部排序为@1,@2,@3,@4,@5,@6


用四种方法实现和输出


第一种:


for(int i = 0; i<array.count;i++)

{

    int elm = [array[i] intValue];

    int val = [value intValue];

    if (val < elm) {

        [array insertObject:value atIndex:i];

        break;

    }

}


for(int i = 0;i<array.count;i++)

{

    NSLog(@"%@",array[i]);

}


第二种:


for (id obj in array) {

    unsigned long i = [array indexOfObject:obj];

    if([value intValue]<[array[i] intValue])

    {

        [array insertObject:value atIndex:i];

        break;

    }

}


for (id obj in array) {

    NSLog(@"%@",obj);

}


第三种:


NSEnumerator *enumerator = [array objectEnumerator];


id obj = nil;


while (obj = [enumerator nextObject]) {

    unsigned long i = [array indexOfObject:obj];

    if([value intValue]<[array[i] intValue])

    {

        [array insertObject:value atIndex:i];

        break;

    }

}


NSEnumerator *enumerator1 = [array objectEnumerator];

obj = nil;

while (obj = [enumerator1 nextObject]) {

    NSLog(@"%@",obj);

}


第四种:


[array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx,BOOL *stop) {

    if([value intValue]<[array[idx] intValue])

    {

        [array insertObject:value atIndex:idx];

        *stop = YES;

    }

}];


[array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

    NSLog(@"%lu - %@",idx,obj);

}]; 

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黑马程序员--NSArray遍历