{"id":1019,"date":"2021-12-12T07:32:29","date_gmt":"2021-12-12T07:32:29","guid":{"rendered":"https:\/\/swatilathia.wordpress.com\/?page_id=1019"},"modified":"2024-12-18T05:26:04","modified_gmt":"2024-12-18T05:26:04","slug":"javascript-tutorial-3-built-in-functions","status":"publish","type":"page","link":"https:\/\/swatilathia.com\/?page_id=1019","title":{"rendered":"JavaScript Tutorial 3 – Built In Functions"},"content":{"rendered":"\n

\n

Table of Contents<\/p>\nToggle<\/span>

Date Functions<\/a><\/li><\/ul><\/nav><\/div>\n

<\/span>String Functions<\/strong><\/span><\/h2>\n\n\n\n
\n
charAt()<\/strong><\/li>\n\n\n\n
It is a method that returns the character from the specified index.<\/li>\n\n\n\n
Characters in a string are indexed from left to right. The index of the first character is 0, and the index of the last character in a string, called stringName, is stringName.length \u2013 1.<\/li>\n\n\n\n
Syntax: <\/strong>string.charAt(index);<\/li>\n\n\n\n
index \u2212 An integer between 0 and 1 less than the length of the string.<\/li>\n\n\n\n
Return Value: <\/strong>Returns the character from the specified index.<\/li>\n<\/ul>\n\n\n\n
<body> \n \t <script type = \"text\/javascript\">\n var str = new String( \"This is string\" );\n document.writeln(\"str.charAt(0) is:\"+str.charAt(0)); \n document.writeln(\"<br>str.charAt(1) is:\"+str.charAt(1)); \n document.writeln(\"<br>str.charAt(2) is:\"+str.charAt(2)); \n document.writeln(\"<br>str.charAt(3) is:\"+str.charAt(3)); \n document.writeln(\"<br>str.charAt(4) is:\"+str.charAt(4)); \n document.writeln(\"<br>str.charAt(5) is:\"+str.charAt(5)); \n <\/script> \n<\/body><\/code><\/pre>\n\n\n\n\ncharCodeAt()<\/strong><\/li>\n\n\n\n This method returns a number indicating the Unicode value of the character at the given index.<\/li>\n\n\n\n Unicode code points range from 0 to 1,114,111. The first 128 Unicode code points are a direct match of the ASCII character encoding. charCodeAt() always returns a value that is less than 65,536.<\/li>\n\n\n\n Syntax: <\/strong>string.charCodeAt(index);<\/li>\n\n\n\n index \u2212 <\/strong>An integer between 0 and 1 less than the length of the string; if unspecified, defaults to 0.<\/li>\n\n\n\n Return Value: <\/strong>Returns a number indicating the Unicode value of the character at the given index. It returns NaN if the given index is not between 0 and 1 less than the length of the string.<\/li>\n<\/ul>\n\n\n\n<body> \n\t<script type = \"text\/javascript\">\n var str = new String(\"Bhavan's H J Doshi Jamnagar\");\n document.writeln(str.charCodeAt(0)); \n document.writeln(\"<br>\"+ str.charCodeAt(1)); \n document.writeln(\"<br>\" + str.charCodeAt(2)); \n document.writeln(\"<br>\" + str.charCodeAt(3)); \n document.writeln(\"<br>\" + str.charCodeAt(4)); \n document.writeln(\"<br>\" + str.charCodeAt(5)); \n <\/script> \n<\/body><\/code><\/pre>\n\n\n\n\nconcat()<\/strong><\/li>\n\n\n\n This method adds two or more strings and returns a new single string. <\/li>\n\n\n\n Syntax: string.concat(string2, string3, \u2026,stringN);<\/li>\n\n\n\n String2\u2026stringN<\/strong> \u2212 These are the strings to be concatenated.<\/li>\n\n\n\n Return Value<\/strong>: Returns a single concatenated string.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\nvar str1 = new String( \"This is string one\" );\nvar str2 = new String( \" This is string two\" );\nvar str3 = str1.concat(str2); \ndocument.write(\"Concatenated String :\" + str3); \n<\/script> \n<\/code><\/pre>\n\n\n\n\nindexOf()<\/strong><\/li>\n\n\n\n This method returns the index within the calling String object of the first occurrence of the specified value, starting the search at fromIndex or -1 if the value is not found.<\/li>\n\n\n\n Syntax: string.indexOf(searchValue[, fromIndex])<\/li>\n\n\n\n searchValue<\/strong> \u2212 A string representing the value to search for.<\/li>\n\n\n\n fromIndex<\/strong> \u2212 The location within the calling string to start the search from. It can be any integer between 0 and the length of the string. The default value is 0.<\/li>\n\n\n\n Return Value: <\/strong>Returns the index of the found occurrence, otherwise -1 if not found.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n var str1 = new String( \"This is HJDoshi\" );\n var index = str1.indexOf(\"is\");\n document.write(\"indexOf found String :\" + index ); \n document.write(\"<br>\");\n var index = str1.indexOf(\"Doshi\");\n document.write(\"indexOf found String :\" + index ); \n<\/script><\/code><\/pre>\n\n\n\n\nlastIndexOf()<\/strong><\/li>\n\n\n\n This method returns the index within the calling String object of the last occurrence of the specified value, starting the search at fromIndex or -1 if the value is not found.<\/li>\n\n\n\n Syntax: string.lastIndexOf(searchValue[, fromIndex])<\/li>\n\n\n\n searchValue<\/strong> \u2212 A string representing the value to search for.<\/li>\n\n\n\n fromIndex<\/strong> \u2212 The location within the calling string to start the search from. It can be any integer between 0 and the length of the string. The default value is 0.<\/li>\n\n\n\n Return Value<\/strong>: Returns the index of the last found occurrence, otherwise -1 if not found.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n var str1 = new String( \"This is HJDoshi\" );\n var index = str1.lastIndexOf(\"is\");\n document.write(\"indexOf found String :\" + index ); \n document.write(\"<br>\");\n var index = str1.lastIndexOf(\"Doshi\");\n document.write(\"indexOf found String :\" + index ); \n<\/script><\/code><\/pre>\n\n\n\n\nslice()<\/strong><\/li>\n\n\n\n This method extracts a section of a string and returns a new string.<\/li>\n\n\n\n Syntax: <\/strong>string.slice( beginslice [, endSlice] );<\/li>\n\n\n\n beginSlice<\/strong> \u2212 The zero-based index at which to begin extraction.<\/li>\n\n\n\n endSlice<\/strong> \u2212 The zero-based index at which to end extraction. If omitted, slice extracts to the end of the string.<\/li>\n\n\n\n Return Value:<\/strong> If successful, slice returns the index of the regular expression inside the string. Otherwise, it returns -1.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n\tvar str1 = new String(\"This is HJDoshi\");\n\tdocument.write(str1.slice(-7,-1)); \n<\/script> <\/code><\/pre>\n\n\n\n\nsplit()<\/strong><\/li>\n\n\n\n This method splits a String object into an array of strings by separating the string into substrings.<\/li>\n\n\n\n Syntax: string.split([separator][, limit]);<\/li>\n\n\n\n separator<\/strong> \u2212 Specifies the character to use for separating the string. If separator is omitted, the array returned contains one element consisting of the entire string.<\/li>\n\n\n\n limit<\/strong> \u2212 Integer specifying a limit on the number of splits to be found.<\/li>\n\n\n\n Return Value: <\/strong>The split method returns the new array. Also, when the string is empty, split returns an array containing one empty string, rather than an empty array.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n var str1 = new String(\"This is HJDoshi\");\n document.write(str1.split(\" \",3)); \n<\/script> <\/code><\/pre>\n\n\n\n\ntoLowerCase()<\/strong><\/li>\n\n\n\n This method returns the calling string value converted to lowercase.<\/li>\n\n\n\n Syntax: <\/strong>string.toLowerCase( )<\/li>\n\n\n\n Return Value<\/strong>: Returns the calling string value converted to lowercase.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \t\tvar str1 = new String(\"This is HJDoshi\");\n \t\tdocument.write(str1.toLowerCase()); \n<\/script><\/code><\/pre>\n\n\n\n\ntoUpperCase()<\/strong><\/li>\n\n\n\n This method returns the calling string value converted to uppercase.<\/li>\n\n\n\n Syntax: <\/strong>string.toUpperCase( )<\/li>\n\n\n\n Return Value: <\/strong>Returns a string representing the specified object.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \tvar str1 = new String(\"This is HJDoshi\");\n \tdocument.write(str1.toUpperCase()); \n<\/script> <\/code><\/pre>\n\n\n\n<\/span>Math Functions<\/strong><\/span><\/h2>\n\n\n\n\nabs()<\/strong><\/li>\n\n\n\n This method returns the absolute value of a number.<\/li>\n\n\n\n Syntax:<\/strong> Math.abs( x ) ;<\/li>\n\n\n\n x \u2212<\/strong> A number<\/li>\n\n\n\n Return Value: <\/strong>Returns the absolute value of a number.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n var a = Math.abs(-10);\n document.write(a); \n<\/script><\/code><\/pre>\n\n\n\n\nceil()<\/strong><\/li>\n\n\n\n This method returns the smallest integer greater than or equal to a number.<\/li>\n\n\n\n Syntax:<\/strong> Math.ceil( x ) ;<\/li>\n\n\n\n x \u2212<\/strong> A numbers.<\/li>\n\n\n\n Return Value<\/strong>: Returns the smallest integer greater than or equal to a number.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \t\tvar a = Math.ceil(-4.3);\n \t\tdocument.write(a); \n<\/script><\/code><\/pre>\n\n\n\n\nfloor()<\/strong><\/li>\n\n\n\n This method returns the largest integer less than or equal to a number.<\/li>\n\n\n\n Syntax: Math.floor( x ) ;<\/li>\n\n\n\n x \u2212 A numbers.<\/li>\n\n\n\n Return Value:<\/strong> Returns the largest integer less than or equal to a number x.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \t\tvar a = Math.floor(-4.3);\n \t\tdocument.write(a); \n<\/script><\/code><\/pre>\n\n\n\n\nlog()<\/strong><\/li>\n\n\n\n This method returns the natural logarithm (base E) of a number. If the value of number is negative, the return value is always NaN.<\/li>\n\n\n\n Syntax: Math.log( x ) ;<\/li>\n\n\n\n x \u2212 A numbers.<\/li>\n\n\n\n Return Value:<\/strong> Returns the natural logarithm (base E) of a number.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \t\tvar a = Math.log(10);\n \t\tdocument.write(a); \n<\/script> <\/code><\/pre>\n\n\n\n\nmax()<\/strong><\/li>\n\n\n\n This method returns the largest of zero or more numbers. If no arguments are given, the results is \u2013Infinity.<\/li>\n\n\n\n Syntax: Math.max(value1, value2, \u2026 valueN ) ;<\/li>\n\n\n\n value1, value2, \u2026 valueN : Numbers.<\/li>\n\n\n\n Return Value:<\/strong> Returns the largest of zero or more numbers.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \t\tvar a = Math.max(10,-3,0,200);\n \t\tdocument.write(a); \n<\/script><\/code><\/pre>\n\n\n\n\nmin()<\/strong><\/li>\n\n\n\n This method returns the smallest of zero or more numbers. If no arguments are given, the results is +Infinity.<\/li>\n\n\n\n Syntax: Math.min(value1, value2, \u2026 valueN ) ;<\/li>\n\n\n\n value1, value2, \u2026 valueN : Numbers.<\/li>\n\n\n\n Return Value: Returns the smallest of zero or more numbers.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \t\tvar a = Math.min(10,-3,0,200);\n \t\tdocument.write(a); \n<\/script><\/code><\/pre>\n\n\n\n\npow()<\/strong><\/li>\n\n\n\n This method returns the base to the exponent power, that is, baseexponent.<\/li>\n\n\n\n Syntax: Math.pow(base, exponent ) ;<\/li>\n\n\n\n base \u2212 The base number.<\/li>\n\n\n\n exponents \u2212 The exponent to which to raise base.<\/li>\n\n\n\n Return Value:<\/strong> Returns the base to the exponent power, that is, base exponent.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \t\tvar a = Math.pow(7,3);\n \t\tdocument.write(a); \n<\/script> <\/code><\/pre>\n\n\n\n\nrandom()<\/strong><\/li>\n\n\n\n This method returns a random number between 0 (inclusive) and 1 (exclusive).<\/li>\n\n\n\n Syntax: Math.random() ;<\/li>\n\n\n\n Return Value:<\/strong> Returns a random number between 0 (inclusive) and 1 (exclusive).<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n var a = Math.random();\n document.write(a); \n<\/script><\/code><\/pre>\n\n\n\n\nround()<\/strong><\/li>\n\n\n\n This method returns the value of a number rounded to the nearest integer.<\/li>\n\n\n\n Syntax: Math.round( x ) ;<\/li>\n\n\n\n Return Value: Returns the value of a number rounded to the nearest integer.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n var a = Math.round(-20.3);\n document.write(a); \n<\/script><\/code><\/pre>\n\n\n\n\nsqrt()<\/strong><\/li>\n\n\n\n This method returns the square root of a number. If the value of a number is negative, sqrt returns NaN.<\/li>\n\n\n\n Syntax: Math.sqrt( x ) ;<\/li>\n\n\n\n x \u2212 A number<\/li>\n\n\n\n Return Value: Returns the square root of a given number.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \t\tvar a = Math.sqrt(100);\n \t\tdocument.write(a); \n<\/script><\/code><\/pre>\n\n\n\n<\/span>Array Functions<\/strong><\/span><\/h2>\n\n\n\n\nconcat()<\/strong><\/li>\n\n\n\n It combines two or more arrays and returns a new string. This method doesn\u2019t make any change in the original array.<\/li>\n\n\n\n Syntax: array.concat(arr1,arr2,\u2026.,arrn)\u00a0<\/li>\n\n\n\n arr1,arr2,\u2026.,arrn \u2013 It represent the arrays to be combined.<\/li>\n\n\n\n Return<\/strong>: A new array object that represents a joined array.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \t\t var arr1=[\"C\",\"C++\",\"Python\"]; \n\t \t var arr2=[\"Java\",\"JavaScript\",\"Android\"]; \n\t\t var result=arr1.concat(arr2); \n\t\t document.write(result); \n<\/script><\/code><\/pre>\n\n\n\n\njoin()<\/strong><\/li>\n\n\n\n It combines all the elements of an array into a string and return a new string. We can use any type of separators to separate given array elements.<\/li>\n\n\n\n Syntax: array.join(separator)\u00a0<\/li>\n\n\n\n Separator() \u2013 It is optional. It represents the separator used between array elements.<\/li>\n\n\n\n Return: A new string contains the array values with specified separator.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \t\tvar arr1=[\"C\",\"C++\",\"Python\"]; \n\t\tvar result=arr1.join(); \n\t\tdocument.write(result); \n<\/script><\/code><\/pre>\n\n\n\n\npop()<\/strong><\/li>\n\n\n\n It removes the last element from the given array and return that element. This method changes the length of the original array.<\/li>\n\n\n\n Syntax<\/strong>: array.pop()\u00a0 <\/li>\n\n\n\n Return<\/strong>: The last element of given array.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n \tvar arr1=[\"C\",\"C++\",\"Python\"]; \n\t\tvar result=arr1.pop(); \n\t\tdocument.write(\"The deleted element = \",result,\"<br>\"); \n\t\tdocument.write(\"Now the new array = \",arr1);\n<\/script><\/code><\/pre>\n\n\n\n\npush()<\/strong><\/li>\n\n\n\n It adds one or more elements to the end of the given array. This method changes the length of the original array.<\/li>\n\n\n\n Syntax<\/strong>: array.push(element1,element2\u2026.elementn)\u00a0<\/li>\n\n\n\n element1,element2\u2026.elementn \u2013 The elements to be added. <\/li>\n\n\n\n Return:<\/strong> The original array with added elements.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n var arr1=[\"C\",\"C++\",\"Python\"]; \n\tvar result=arr1.push(\"Java\",\"JavaScript\"); \n\tdocument.write(\"The new length of an array = \",result,\"<br>\");\n\tdocument.write(\"Now the new array = \",arr1);\n<\/script> <\/code><\/pre>\n\n\n\n\nshift()<\/strong><\/li>\n\n\n\n It removes the first element of the given array and returns that element. This method changes the length of the original array.<\/li>\n\n\n\n Syntax<\/strong>: array. shift()\u00a0<\/li>\n\n\n\n Return<\/strong>: The first element of an array.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n var arr1=[\"C\",\"C++\",\"Python\"]; \n\tvar result=arr1.shift(); \n\tdocument.write(\"The deleted element = \",result,\"<br>\");\n\tdocument.write(\"Now the array = \",arr1);\n<\/script><\/code><\/pre>\n\n\n\n\nunshift()<\/strong><\/li>\n\n\n\n It adds one or more elements to the beginning of an array.<\/li>\n\n\n\n Syntax<\/strong>: array.unshift()\u00a0<\/li>\n\n\n\n Return<\/strong>: The new length of an array.<\/li>\n<\/ul>\n\n\n\n<script type = \"text\/javascript\">\n var arr1=[\"C\",\"C++\",\"Python\"]; \n\tvar result=arr1.unshift(\"ASP.net\",\"Java\"); \n\tdocument.write(\"The length of an array = \",result,\"<br>\");\n\tdocument.write(\"Now the new array = \",arr1);\n<\/script><\/code><\/pre>\n\n\n\n<\/span>Date Functions<\/strong><\/span><\/h2>\n\n\n\n\nThe JavaScript date object can be used to get year, month and day.<\/li>\n<\/ul>\n\n\n\n\ngetDate()<\/strong><\/li>\n\n\n\n This method returns the day for the specified date on the basis of local time.<\/li>\n\n\n\n Syntax: <\/strong>dateObj.getDate()<\/li>\n<\/ul>\n\n\n\n\ngetDay()<\/strong><\/li>\n\n\n\n This method returns the value of day of the week for the specified date on the basis of local time. The value of the day starts with 0 that represents Sunday.<\/li>\n\n\n\n Syntax:<\/strong> dateObj.getDay()\u00a0<\/li>\n<\/ul>\n\n\n\n\ngetFullYear()<\/strong><\/li>\n\n\n\n This method returns the year for the specified date on the basis of universal time.<\/li>\n\n\n\n Syntax:<\/strong> dateObj.getFullYear()<\/li>\n<\/ul>\n\n\n\n\ngetMonth()<\/strong><\/li>\n\n\n\n This method returns the integer value that represents month in the specified date on the basis of local time. The value returned by getMonth() method starts with 0 that represents January.<\/li>\n\n\n\n Syntax:<\/strong> dateObj.getMonth()\u00a0<\/li>\n<\/ul>\n\n\n\n\ngetHours()<\/strong><\/li>\n\n\n\n This method returns the hour for the specified date on the basis of local time.<\/li>\n\n\n\n Syntax: <\/strong>dateObj.getHours()\u00a0<\/li>\n<\/ul>\n\n\n\n\ngetMinutes()<\/strong><\/li>\n\n\n\n This method returns the minutes in the specified date on the basis of local time.<\/li>\n\n\n\n Syntax:<\/strong> dateObj.getMinutes()\u00a0<\/li>\n<\/ul>\n\n\n\n\ngetSeconds()<\/strong><\/li>\n\n\n\n This method returns the seconds in the specified date on the basis of local time.<\/li>\n\n\n\n Syntax:<\/strong> dateObj.getSeconds()\u00a0<\/li>\n<\/ul>\n\n\n\n\ngetMilliseconds()<\/strong><\/li>\n\n\n\n This method returns the value of milliseconds in specified date on the basis of local time.<\/li>\n\n\n\n Syntax:<\/strong> dateObj.getMilliseconds()\u00a0<\/li>\n<\/ul>\n\n\n\n<script language=\"javascript\"> \n var dt=new Date(); \n document.write(dt);\n document.write(\"Today's date \".dt.getDate()); \n document.write(\"Today is \".dt.getDay()); \n document.write(\"Current Year is \".dt.getFullYear()); \n document.write(\"Current Month is \".dt.getMonth());\n document.write(\"Current Hour is \".dt.getHours()); \n document.write(\"Current Minute is \".dt.getMinutes());\n document.write(\"Current Second is \".dt.getSeconds()); \n document.write(\"Current millisecond is \".dt.getMilliseconds());\n<\/script><\/code><\/pre>\n<\/body>","protected":false},"excerpt":{"rendered":"String Functions Math Functions Array Functions Date Functions<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"zakra_page_container_layout":"customizer","zakra_page_sidebar_layout":"customizer","zakra_remove_content_margin":false,"zakra_sidebar":"customizer","zakra_transparent_header":"customizer","zakra_logo":0,"zakra_main_header_style":"default","zakra_menu_item_color":"","zakra_menu_item_hover_color":"","zakra_menu_item_active_color":"","zakra_menu_active_style":"","zakra_page_header":true,"om_disable_all_campaigns":false,"footnotes":""},"class_list":["post-1019","page","type-page","status-publish","hentry"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swatilathia.com\/index.php?rest_route=\/wp\/v2\/pages\/1019","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/swatilathia.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/swatilathia.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/swatilathia.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/swatilathia.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1019"}],"version-history":[{"count":4,"href":"https:\/\/swatilathia.com\/index.php?rest_route=\/wp\/v2\/pages\/1019\/revisions"}],"predecessor-version":[{"id":5613,"href":"https:\/\/swatilathia.com\/index.php?rest_route=\/wp\/v2\/pages\/1019\/revisions\/5613"}],"wp:attachment":[{"href":"https:\/\/swatilathia.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1019"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}