{"id":17436,"date":"2023-10-09T09:03:54","date_gmt":"2023-10-09T08:03:54","guid":{"rendered":"https:\/\/www.baeldung.com\/java-convert-char-int-array"},"modified":"2023-10-09T09:03:54","modified_gmt":"2023-10-09T08:03:54","slug":"convert-char-array-to-int-array-in-java","status":"publish","type":"post","link":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/2023\/10\/09\/convert-char-array-to-int-array-in-java\/","title":{"rendered":"Convert Char Array to Int Array in Java"},"content":{"rendered":"

\"\"<\/p>\n

1. Overview<\/h2>\n
<\/div>\n

In this short tutorial, we’ll explore different ways of converting a char<\/em> array to an int<\/em> array in Java.<\/p>\n

First, we’ll use methods and classes from Java 7. Then, we’ll see how to achieve the same objective using Java 8 Stream API<\/a>.<\/p>\n

2. Using Character<\/em> Class<\/h2>\n
<\/div>\n

The Character<\/em> class wraps a char<\/em> value in an object. It provides various methods to work and manipulate primitive characters as objects<\/strong>.<\/p>\n

Among these handy methods, we find getNumericValue()<\/em><\/a> and digit()<\/em><\/a>. So, let’s dig in and see how to use them to convert a char<\/em> array into an int<\/em> array.<\/p>\n

2.1. Character#getNumericValue()<\/em><\/h3>\n
<\/div>\n

This method offers a straightforward and concise way to return the int<\/em> value of the given character. For instance, the character ‘6’<\/em> will return 6.<\/p>\n

So, let’s see in action:<\/p>\n

int[] usingGetNumericValueMethod(char[] chars) {\r\n    if (chars == null) {\r\n        return null;\r\n    }\r\n    int[] ints = new int[chars.length];\r\n    for (int i = 0; i < chars.length; i++) {\r\n        ints[i] = Character.getNumericValue(chars[i]);\r\n    }\r\n    return ints;\r\n}<\/code><\/pre>\n
As we can see, we iterated through the char<\/em> array. Then, we called the getNumericValue()<\/em> to get the integer value of each character.<\/p>\n
An important caveat is that if the specified character does not have any int<\/em> value, -1 is returned instead<\/strong>.<\/p>\n
Please bear in mind that we can rewrite our traditional loop in a more functional way:<\/p>\n
Arrays.setAll(ints, i -> Character.getNumericValue(chars[i]));<\/code><\/pre>\n
Now, let’s add a test case:<\/p>\n
@Test\r\nvoid givenCharArray_whenUsingGetNumericValueMethod_shouldGetIntArray() {\r\n    int[] expected = { 2, 3, 4, 5 };\r\n    char[] chars = { '2', '3', '4', '5' };\r\n    int[] result = CharArrayToIntArrayUtils.usingGetNumericValueMethod(chars);\r\n    assertArrayEquals(expected, result);\r\n}<\/code><\/pre>\n
2.2. Character#digit()<\/em><\/h3>\n
<\/div>\n
Typically, digit(char ch, int radix)<\/em> is another method that we can use to address our central question. This method returns the numeric value of the given character based on the specified radix.<\/p>\n
Now, let’s exemplify how to use digit()<\/em> to convert an array of characters into an array of integers:<\/p>\n
int[] usingDigitMethod(char[] chars) {\r\n    int[] ints = new int[chars.length];\r\n    for (int i = 0; i < chars.length; i++) {\r\n        ints[i] = Character.digit(chars[i], 10);\r\n    }\r\n    return ints;\r\n}<\/code><\/pre>\n
In short, the most common radix is 10, which denotes the decimal system (0-9). For example, the character ‘7’ in base 10 is simply equal to 7<\/strong>.<\/p>\n
Lastly, we’ll create another test case to confirm our method:<\/p>\n
@Test\r\nvoid givenCharArray_whenUsingDigitMethod_shouldGetIntArray() {\r\n    int[] expected = { 1, 2, 3, 6 };\r\n    char[] chars = { '1', '2', '3', '6' };\r\n    int[] result = CharArrayToIntArrayUtils.usingDigitMethod(chars);\r\n    assertArrayEquals(expected, result);\r\n}<\/code><\/pre>\n
3. Using the Stream API<\/h2>\n
<\/div>\n
Alternatively, we can use the stream API to process the char<\/em> array to int<\/em> array conversion. So, let’s see it in practice:<\/p>\n
int[] usingStreamApiMethod(char[] chars) {\r\n    return new String(chars).chars()\r\n      .map(c -> c - 48)\r\n      .toArray();\r\n}<\/code><\/pre>\n
As shown above, we created a String<\/em> object from the char<\/em> array. Then, we used the chars()<\/em> and map()<\/em> methods to transform each character into an int<\/em> value.<\/p>\n
Please note that the character ‘0’ is 48 in ASCII, ‘1’ is 49, and so on. Thus, ‘0’ – 48 equals 0, and so on. This why subtracting by 48 translates the characters ‘0’..’9′ to the values 0..9<\/strong>.<\/p>\n
Next, let’s add another test case:<\/p>\n
@Test\r\nvoid givenCharArray_whenUsingStreamApi_shouldGetIntArray() {\r\n    int[] expected = { 9, 8, 7, 6 };\r\n    char[] chars = { '9', '8', '7', '6' };\r\n    int[] result = CharArrayToIntArrayUtils.usingStreamApiMethod(chars);\r\n    assertArrayEquals(expected, result);\r\n}<\/code><\/pre>\n
4. Using Integer#parseInt()<\/em><\/h2>\n
<\/div>\n
parseInt()<\/em><\/a> is another great option to consider when converting a char<\/em> into an int<\/em>. This method lets us get the primitive int<\/em> value of a given string:<\/p>\n
int[] usingParseIntMethod(char[] chars) {\r\n    int[] ints = new int[chars.length];\r\n    for (int i = 0; i < chars.length; i++) {\r\n        ints[i] = Integer.parseInt(String.valueOf(chars[i]));\r\n    }\r\n    return ints;\r\n}<\/code><\/pre>\n
Here, we need to convert each character into a string first before returning the int value.<\/p>\n
As always, we’ll create a test case to unit test our method:<\/p>\n
@Test\r\nvoid givenCharArray_whenUsingParseIntMethod_shouldGetIntArray() {\r\n    int[] expected = { 9, 8, 7, 6 };\r\n    char[] chars = { '9', '8', '7', '6' };\r\n    int[] result = CharArrayToIntArrayUtils.usingParseIntMethod(chars);\r\n    assertArrayEquals(expected, result);\r\n}<\/code><\/pre>\n
5. Conclusion<\/h2>\n
<\/div>\n
In this short article, we explained in detail how to convert a char<\/em> array into an int<\/em> array in Java.<\/p>\n
As always, the full code used in the article is available over on GitHub<\/a>.<\/p>\n
\"\"<\/p>\n
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\"\"<\/p>\n
Explore how to convert a char array to an int array in Java.<\/p>\n
<\/a>\u00a0<\/a>\u00a0<\/a>\u00a0<\/a>\u00a0<\/a>\u00a0<\/a>\u00a0<\/a>\u00a0<\/div>\n","protected":false},"author":293,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"site-container-style":"default","site-container-layout":"default","site-sidebar-layout":"default","disable-article-header":"default","disable-site-header":"default","disable-site-footer":"default","disable-content-area-spacing":"default","footnotes":""},"categories":[22],"tags":[61,122,127,129,124,128,125,132,131,133,126,130,123,66,94,88,97,56,64,65,60,112,40,75,95,104,33,120,105,101,98,115,30,29,41,86,70,69,68,72,71,26,118,108,87,46,55,48,52,54,51,50,83,62,58,57,109,35,59,63,85,79,82,96,80,27,81,114,44,42,43,45,38,39,110,117,100,111,116,73,89,90,92,91,93,84,78,37,102,34,36,77,67,74,99,113,119,28,121,32,47,49,53,103,31,76],"class_list":["post-17436","post","type-post","status-publish","format-standard","hentry","category-mobile","tag-airpods","tag-anime","tag-anime-characters","tag-anime-cosplay","tag-anime-edits","tag-anime-merchandise","tag-anime-movies","tag-anime-news","tag-anime-recommendations","tag-anime-reviews","tag-anime-series","tag-anime-streaming","tag-animes","tag-app-store","tag-app-store-samsung","tag-appgallery","tag-appgallery-oneplus","tag-apple","tag-apple-music","tag-apple-tv","tag-apple-watch","tag-bbc-sport","tag-best-mobile-games","tag-bixby","tag-bixby-xiaomi","tag-champions-league","tag-cyberpunk","tag-cyberpunk-2077","tag-fantasy-football","tag-fifa","tag-football","tag-formula-1","tag-fortnite","tag-free-fire","tag-free-mobile-games","tag-freebuds-pro","tag-galaxy-a52","tag-galaxy-note-20","tag-galaxy-s21","tag-galaxy-watch-4","tag-galaxy-z-fold-3","tag-game","tag-games","tag-golf","tag-harmonyos","tag-how-to-backup-iphone","tag-how-to-factory-reset-iphone","tag-how-to-reset-iphone","tag-how-to-restore-iphone","tag-how-to-unlock-iphone","tag-how-to-unlock-iphone-5","tag-how-to-unlock-iphone-6","tag-huawei","tag-ios","tag-ipad","tag-iphone","tag-live-soccer","tag-lol","tag-macbook","tag-macos","tag-mate-40-pro","tag-mi-11-lite","tag-mi-home-security-camera-basic-1080p","tag-mi-home-security-camera-basic-1080p-huawei","tag-mi-smart-band-6","tag-minecraft","tag-miui","tag-mlb-scores","tag-mobile-game-design","tag-mobile-game-development","tag-mobile-game-marketing","tag-mobile-game-monetization","tag-mobile-games","tag-mobile-gaming","tag-nba-scores","tag-nba-standings","tag-nfl","tag-nfl-scores","tag-nhl-scores","tag-one-ui","tag-oneplus","tag-oneplus-9-pro","tag-oneplus-buds-pro","tag-oneplus-nord-ce-5g","tag-oxygenos","tag-p40-pro-plus","tag-poco-x3-pro","tag-pokemon","tag-premier-league","tag-pubg","tag-pubg-mobile","tag-redmi-note-10-pro","tag-samsung","tag-samsung-pay","tag-soccer","tag-sports","tag-steam","tag-steeam","tag-top-10-anime","tag-valorant","tag-when-do-the-iphone-7-come-out","tag-when-does-the-iphone-7-come-out","tag-when-is-the-iphone-7-coming-out","tag-world-cup","tag-xbox-series-x","tag-xiaomi"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/posts\/17436","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/users\/293"}],"replies":[{"embeddable":true,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/comments?post=17436"}],"version-history":[{"count":1,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/posts\/17436\/revisions"}],"predecessor-version":[{"id":17437,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/posts\/17436\/revisions\/17437"}],"wp:attachment":[{"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/media?parent=17436"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/categories?post=17436"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/tags?post=17436"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}