Select find all in Objective-C

To find all elements of an array satisfying a condition in Objective-C, you can use the NSPredicate class. NSPredicate allows you to define a condition or set of conditions that the elements of the array must meet. Here are some examples of how to apply NSPredicate:

Example 1: Finding all even numbers in an array of integers

``objective-c NSArray *numbersArray = @[@1, @2, @3, @4, @5, @6]; //declare the array


NSPredicate *evenPredicate = [NSPredicate predicateWithBlock:^BOOL(NSNumber *number, NSDictionary *bindings) {

    return [number intValue] % 2 == 0; //check if the number is even

}];
NSArray *evenNumbersArray = [numbersArray filteredArrayUsingPredicate:evenPredicate];

NSLog(@"Even Numbers: %@", evenNumbersArray); //output: Even Numbers: (2, 4, 6)



In this example, we declare an array of numbers and then create a NSPredicate with a block that checks if the number is even. We apply this predicate to the numbersArray using the filteredArrayUsingPredicate method, which creates a new array of numbers that meet the condition.
Example 2: Finding all strings that contain a certain substring in an array of strings
objective-c

NSArray *stringsArray = @[@"apple", @"banana", @"orange", @"grapefruit", @"strawberry"]; //declare the array
NSString *substring = @"an";
NSPredicate *containsSubstringPredicate = [NSPredicate predicateWithBlock:^BOOL(NSString *string, NSDictionary *bindings) {

    return [string rangeOfString:substring options:NSCaseInsensitiveSearch].location != NSNotFound; //check if the string contains the substring

}];

NSArray *stringsContainingSubstringArray = [stringsArray filteredArrayUsingPredicate:containsSubstringPredicate]; NSLog(@"Strings containing '%@': %@", substring, stringsContainingSubstringArray); //output: Strings containing 'an': (banana, orange, grapefruit)`

In this example, we declare an array of strings and a substring to search for. We then create a NSPredicate with a block that checks if the string contains the substring. We apply this predicate to the stringsArray using the filteredArrayUsingPredicate method, which creates a new array of strings that meet the condition.

Conclusion: NSPredicate` provides a flexible and powerful way to filter arrays in Objective-C based on any condition or set of conditions you need.

Select find all in Objective-C

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