To re-index an array in PHP, the code is as follows −Example Live DemoOutputThis will produce the following output−Array... Key = 0, Value = 150  Key = 1, Value = 100 Key = 2, Value = 120 Key = 3, Value = 110 Key = 4, Value = 115 Array after re-indexing Key = 2, Value = 150 Key = 3, Value = 100 Key = 4, Value = 120 Key = 5, Value = 110 Key = 6, Value = 115ExampleLet us now see another example − Live DemoOutputThis will produce the following output−Array... Key = a, Value = 150 Key = b, Value = 100 Key = c, Value = 120 Key = d, Value = 110 Key = e, Value = 115 Array after re-indexing Key = b, Value = 150 Key = c, Value = 100 Key = d, Value = 120 Key = e, Value = 110 Key = f, Value = 115

To trim all strings in an array in PHP, the code is as follows−Example Live DemoOutputThis will produce the following output−Array with leading and trailing whitespaces... Value = John Value = Jacob Value = Tom Value = Tim Updated Array... Value = John Value = Jacob Value = Tom Value = TimExampleLet us now see another example − Live DemoOutputThis will produce the following output−Array with leading and trailing whitespaces... Value = Kevin Value = Katie Value = Angelina Value = Jack Updated Array... Kevin Katie Angelina Jack

To sort an array of dates in PHP, the code is as follows−Example Live DemoOutputThis will produce the following output−Array (    [0] => 2019-08-10    [1] => 2019-09-08    [2] => 2019-10-10    [3] => 2019-11-11 )ExampleLet us now see another example − Live DemoOutputThis will produce the following output−Array (    [0] => 2019-11-11    [1] => 2019-11-11    [2] => 2019-10-10    [3] => 2019-09-08    [4] => 2019-05-11    [5] => 2019-01-01 )

To check substring in a string, the code is as follows in PHP −Example Live DemoOutputThis will produce the following output−String = How I Met Your Mother Substring = Mother Substring found successfullyExampleLet us now see another example − Live DemoOutputThis will produce the following output−String = In the Heart of Sea Substring = Ocean Substring not found

To add days to $Date in PHP, the code is as follows−Example Live DemoOutputThis will produce the following output−Displaying date... Date = 2019-11-11 Displaying updated date... 2019-12-01ExampleLet us now see another example − Live DemoOutputThis will produce the following output−Displaying Date...2019/11/11 Displaying Updated Date... 2019/12/06

To convert string to boolean in PHP, the code is as follows. Use the filter_val() method−Example Live DemoOutputThis will produce the following output−Displaying Sunday as first day of a week... First day (next week) = Sunday - 15/12/2019 bool(false)ExampleLet us now see another example − Live DemoOutputThis will produce the following output−bool(false) bool(true) bool(false) bool(false)

To get the first day of the week in PHP, the code is as follows −Example Live DemoOutputThis will produce the following output −First day = Monday - 09/12/2019ExampleLet us now see another example − Live DemoOutputThis will produce the following output −Displaying Sunday as first day of a week... First day (next week) = Sunday - 15/12/2019

To get the first element of an array in PHP, the code is as follows −Example Live DemoOutputThis will produce the following output−Array value ... Value 1 = 150ExampleLet us now see another example − Live DemoOutputThis will produce the following output −Value 1 = 150

To get random value out of an array in PHP, the code is as follows−Example Live DemoOutputThis will produce the following output −Array values ... Value 1 = 150 Value 2 = 100 Value 3 = 120 Value 4 = 110 Value 5 = 115 Value 6 = 103 Value 7 = 105 Value 8 = 125 Random value from arary = 110ExampleLet us now see another example − Live DemoOutputThis will produce the following output−Array values ... Value 1 = 150 Value 2 = 100 Value 3 = 120 Value 4 = 110 Value 5 = 115 Value 6 = 103 Value 7 = 105 Value 8 = 125 Random values from array...150 115

To concatenate two strings in PHP, the code is as follows −Example Live DemoOutputThis will produce the following output−1.967 and 1.969 Both the values are equal!ExampleLet us now see another example − Live DemoOutputThis will produce the following output−First Name = Jack Second Name = Sparrow Concatenation = JackSparrow