Dictionary, Set

Nsdictionary * dictionary = [[nsdictionary alloc] initwithobjectsandkeys: @ "value1", @ "key1", @ "value2", @ "key2", @ "V3 ", @ "K3", @ "V5", @ "K5", @ "V4", @ "K4", @ "value6", @ "key6", @ "value7 ", @ "ke7", nil]; nslog (@ "% @", dictionary); // create nsdictionary * dictionary2 = [nsdictionary dictionarywithobjectsandkeys: @ "V1 ", @ "K1", @ "V2", @ "K2", nil]; nslog (@ "% @", dictionary2); nsdictionary * dictionary3 = [nsdictionary dictionarywithobject: @ "value" forkey: @ "key"]; nslog (@ "% @", dictionary3); nsarray * keyarray = [nsarray arraywithobjects: @ "K1 ", @ "K2", @ "K3", nil]; // nsarray * valuearray = [nsarray arraywithobjects: @ "V1", @ "V2 ", @ "V3", nil]; // nsdictionary * dictionary4 = [nsdictionary dictionarywithobjects: keyarray forkeys: valuearray]; nslog (@ "% @", dictionary4 ); // create an empty dictionary nsdictionary * DIC = [nsdictionary dictionary]; // create a dictionary object using a file: command + N-> resource-> property listnsdictionary * dictionary5 = [nsdictionary dictionarywithcontentsoffile: @ "/users/lanou3g/desktop/OC/lesson5-20140425/lesson5-20140425/dictionary. plist "]; nslog (@" % @ ", dictionary5); // return the number of key-value pairs in the dictionary nslog (@" % lD ", [dictionary5 count]); // obtain the valuensstring * value1 = [dictionary5 objectforkey: @ "ly"]; nslog (@ "% @", value1 ); // return all key arrays nsarray * allkeysarray = [dictionary5 allkeys]; nslog (@ "% @", allkeysarray ); // return all value arrays nsarray * allvaluesarray = [dictionary5 allvalues]; nslog (@ "% @", allvaluesarray); // use the key enumerator (get all keys) nsenumerator * enumerator = [dictionary5 keyenumerator]; nsstring * STR = nil; while (STR = [enumerator nextobject]) {nslog (@ "% @", STR );} 4.2 create a variable dictionary nsmutabledictionarynsmutabledictionary * dic1 = [nsmutabledictionary dictionarywithobjectsandkeys: @ "V1", @ "K1", @ "V2", @ "K2", nil]; nsmutabledictionary * dic2 = [nsmutabledictionary dictionarywithobjectsandkeys: @ "V3", @ "K3", @ "V4", @ "K4", @ "V5", @ "K5 ", nil]; // used to splice objects [dic1 addentriesfromdictionary: dic2]; nslog (@ "% @", dic1); // delete an object in the dictionary [dic1 removeobjectforkey: @ "K1"]; nslog (@ "% @", dic1); // delete all dictionary objects [dic1 removeallobjects]; nslog (@ "% @", dic1 ); // set the dictionary [dic1 setdictionary: dic2]; nslog (@ "% @", dic1); 5.1nsset collection object container class // 1. use the class method to create an object nsset * set1 = [nsset set]; // create an empty set object nsset * set2 = [nsset setwithobject: @ "ABC"]; nsset * set3 = [nsset setwithobjects: @ "ABC", @ "AAA", @ "BBB", nil]; nslog (@ "% @", set3 ); nsarray * array = [nsarray arraywithobjects: @ "A", @ "B", @ "C", nil]; nsset * set4 = [nsset setwitharray: array]; // use an array to create nslog (@ "% @", set4); nsset * set5 = [nsset setwithset: set4]; // use a collection to create nslog (@ "% @", set5); // 2. create nsset * set6 = [[nsset alloc] init]; nslog (@ "% @", set6); nsset * set7 = [[nsset alloc] initwithobjects: @ "hello", @ "HHaa", @ "bbjdh", nil]; nslog (@ "% @", set7); nsset * set8 = [[nsset alloc] initwitharray: array]; nslog (@ "% @", set8); nsset * set9 = [[nsset alloc] initwithset: set7]; nslog (@ "% @", set9 ); // 3. returns the number of elements nslog (@ "% lD", [set7 count]); // 4. nsenumerator * enumerator = [set7 objectenumerator]; nsstring * STR = nil; while (STR = [enumerator nextobject]) {nslog (@ "% @", str);} // 5. determine whether two of them have an intersection bool ifhasintersection = [set2 intersectsset: set3]; nslog (@ "% d", ifhasintersection); // 6. determine whether two sets are equal nslog (@ "% d", [set2 isequaltoset: set3]); // 7. determine whether the current collection is a subset nslog (@ "% d", [set2 issubsetofset: set3]); 5.2 variable set nsmutableset // create a set object nsmutableset * mutableset = [nsmutableset setwithcapacity: 4]; [mutableset addobject: @ "AAA"]; nslog (@ "% @", mutableset); // class method to create a variable set nsmutableset * mutableset1 = [nsmutableset setwithobjects: @ "AAA", @ "BBB ", @ "CCC", nil]; nsmutableset * mutableset2 = [nsmutableset setwithobject: @ "AAA"]; // Add an object to the set [mutableset2 addobject: @ "DDD"]; nslog (@ "% @", mutableset2); // delete an object from the set [mutableset2 removeobject: @ "DDD"]; nslog (@ "% @", mutableset2 ); // Add the array object to the set object nsarray * arr = [nsarray arraywithobjects: @ "eee", @ "fff", nil]; [mutableset1 addobjectsfromarray: arr]; nslog (@ "% @", mutableset1); // get the intersection of the two sets. Note the difference between intersectset and intersectsset. The latter is the method to determine whether there is an intersection, the returned bool value [mutableset1 intersectset: mutableset2]; nslog (@ "% @", mutableset1); // subtract another set from one set [mutableset1 minusset: mutableset2]; nslog (@ "% @", mutableset1); // delete all elements from an element [mutableset2 removeallobjects]; nslog (@ "% @", mutableset2 ); // obtain the union of the two sets [mutableset1 unionset: mutableset2]; nslog (@ "% @", mutableset1); nslog (@ "% @", mutableset1 ); // assign a value to the set [mutableset1 setset: mutableset2]; nslog (@ "% @", mutableset1); about array sorting nsarray * array = [nsarrayarraywithobjects: @ "12 ", @ "454", @ "7878", @ "77122", @ "555", @ "9", nil]; nslog (@ "Before sorting: % @", array); // This sorting is performed by string size, not by numerical values. array = [array sortedarrayusingselector: @ selector (compare :)]; nslog (@ "after sorting: % @ ", array); // The following method is required for numerical sorting: array = [array sortedarrayusingfunction: intsort context: NULL]; nslog (@" after sorting: % @", array); The following is the implementation of intsort: nsinteger intsort (ID num1, Id num2, void * context) {int V1 = [num1 intvalue]; int v2 = [num2 intvalue]; if (V1 <V2) returnnsorderedascending; else if (V1> V2) returnnsordereddescending; else returnnsorderedsame;} Arrays can be stored in the dictionary and array // dictionary, the array can be saved into the dictionary nsarray * arr = [nsarray arraywithobjects: @ "1", @ "2", @ "3", nil]; // put the array ARR in the dictionary DIC. nsdictionary * DIC = [nsdictionary dictionarywithobject: arr forkey: @ "array"]; nslog (@ "% @", DIC ); // place the dictionary DIC And array ARR in array arr2. nsarray * arr2 = [nsarray arraywithobjects: arr, DIC, nil]; nslog (@ "% @", arr2 );