Map object to implement the map function

/*** Map object to implement the map function *** size () to obtain the number of map elements * isempty () to determine whether the map is empty * clear () delete all map elements * put (Key, value) add an element (Key, value) * remove (key) to map to delete the elements of the specified key. If yes, true is returned, failed to return false * Get (key) to get the element value of the specified key, failed to return NULL * element (INDEX) to get the element of the specified index (using element. key, element. returns NULL * containskey (key) to determine whether the map contains the element * containsvalue (value) of the specified key) determine whether the map contains the element * keys () of the specified value to obtain the Array (array) * values () of all keys in the map to obtain the Array (array) of all values in the map) */Function Map () {This. elements = new array (); // obtain the number of map elements this. size = function () {return this. elements. length ;}, // determine whether the map is null this. isempty = function () {return (this. elements. length <1) ;}, // Delete All map elements this. clear = function () {This. elements = new array () ;}, // Add the element (Key, value) this to the map. put = function (_ key, _ value) {If (this. containskey (_ key) = true) {If (this. containsvalue (_ value) {If (this. remove (_ key) = true) {This. elements. push ({key: _ key, value: _ value}) ;}} else {This. elements. push ({key: _ key, value: _ value}) ;}} else {This. elements. push ({key: _ key, value: _ value}) ;}}, // Delete the element of the specified key. True is returned for success, and falsethis is returned for failure. remove = function (_ key) {var bln = false; try {for (I = 0; I <this. elements. length; I ++) {If (this. elements [I]. key = _ key) {This. elements. splice (I, 1); Return true ;}} catch (e) {bln = false;} return bln ;}, // gets the element value of the specified key, failed to return nullthis. get = function (_ key) {try {for (I = 0; I <this. elements. length; I ++) {If (this. elements [I]. key = _ key) {return this. elements [I]. value ;}} catch (e) {return NULL ;}, // gets the element of the specified index (using element. key, element. value to obtain the key and value). If the return value fails, nullthis is returned. element = function (_ index) {If (_ index <0 | _ index> = This. elements. length) {return NULL;} return this. elements [_ Index] ;}, // determines whether the map contains the element of the specified key. This. containskey = function (_ key) {var bln = false; try {for (I = 0; I <this. elements. length; I ++) {If (this. elements [I]. key = _ key) {bln = true ;}} catch (e) {bln = false;} return bln ;}, // determine whether the map contains the specified value element this. containsvalue = function (_ value) {var bln = false; try {for (I = 0; I <this. elements. length; I ++) {If (this. elements [I]. value = _ value) {bln = true ;}} catch (e) {bln = false;} return bln ;}, // obtain the Array (array) of all keys in the map this. keys = function () {var arr = new array (); for (I = 0; I <this. elements. length; I ++) {arr. push (this. elements [I]. key) ;}return arr ;}, // obtain the Array (array) of all values in the map this. values = function () {var arr = new array (); for (I = 0; I <this. elements. length; I ++) {arr. push (this. elements [I]. value);} return arr;};/*** rewrite tostring */This. tostring = function () {var S = ""; for (I = 0; I <this. elements. length; I ++) {S + = This. elements [I]. value + "" ;}return s ;};}