How to find Frequency (or occurrence) of characters using Java8 | Program4

𝐅𝐫𝐞𝐪𝐮𝐞𝐧𝐜𝐲 𝐨𝐟 𝐜𝐡𝐚𝐫𝐚𝐜𝐭𝐞𝐫𝐬 𝐮𝐬𝐢𝐧𝐠 𝐉𝐚𝐯𝐚𝟖: 𝐏𝐫𝐨𝐛𝐥𝐞𝐦: Given a string and we need to find out frequency (occurrence) of each character in string. 𝐒𝐨𝐥𝐮𝐭𝐢𝐨𝐧: As we need to calculate count of characters w.r.t. each character so we need a collection which can store Character and it's respective count. So, we can utilize Map 𝐋𝐞𝐭 𝐮𝐬 𝐮𝐧𝐝𝐞𝐫𝐬𝐭𝐚𝐧𝐝 𝐒𝐭𝐞𝐩 𝐛𝐲 𝐒𝐭𝐞𝐩 𝐮𝐬𝐢𝐧𝐠 𝐉𝐚𝐯𝐚𝟖: 𝐒𝐭𝐞𝐩𝟏: Convert String in Int stream using chars() method which will give stream of ASCII value of each character 𝐒𝐭𝐞𝐩𝟐: Convert above Int Stream in to Stream of characters with the help of mapToObj() method of stream. 𝐒𝐭𝐞𝐩𝟑: use collect() terminal method to collect the final result 𝐒𝐭𝐞𝐩𝟒: As we need outcome in the form of Map, we will Collectors.groupingBy() method inside collect method 𝐒𝐭𝐞𝐩𝟓: Collectors.groupingBy() need to group same characters and then need to count each group character 𝐒𝐭𝐞𝐩𝟔: So Collectors.groupingBy() method will use first argument as Function.Identity() to get each char for grouping purpose and internally form ArrayList for each group of same characters 𝐒𝐭𝐞𝐩𝟕: Collectors.groupingBy() will use second argument as another collector to find the size of above group of individual ArrayList 𝐒𝐭𝐞𝐩𝟖: At last we will capture the result in Map Refer to practical demonstration below: Regards, PrinceAutomationDestination