插入元素

Created: November-22, 2018

NSMutableArray *myColors;
int i;
int count;
myColors = [NSMutableArray arrayWithObjects: @"Red", @"Green", @"Blue", @"Yellow", nil];
[myColors insertObject: @"Indigo" atIndex: 1];
[myColors insertObject: @"Violet" atIndex: 3];