diff options
Diffstat (limited to 'dart.html.markdown')
| -rw-r--r-- | dart.html.markdown | 119 |
1 files changed, 95 insertions, 24 deletions
diff --git a/dart.html.markdown b/dart.html.markdown index f8fb06fc..7db9bd33 100644 --- a/dart.html.markdown +++ b/dart.html.markdown @@ -29,6 +29,7 @@ example1() { nested2() => print("Example1 nested 1 nested 2"); nested2(); } + nested1(); } @@ -37,6 +38,7 @@ example2() { nested1(fn) { fn(); } + nested1(() => print("Example2 nested 1")); } @@ -47,9 +49,12 @@ example3() { planA(fn(informSomething)) { fn("Example3 plan A"); } - planB(fn) { // Or don't declare number of parameters. + + planB(fn) { + // Or don't declare number of parameters. fn("Example3 plan B"); } + planA((s) => print(s)); planB((s) => print(s)); } @@ -60,17 +65,20 @@ example4() { nested1(fn(informSomething)) { fn(example4Something); } + nested1((s) => print(s)); } // Class declaration with a sayIt method, which also has closure access // to the outer variable as though it were a function as seen before. var example5method = "Example5 sayIt"; + class Example5Class { sayIt() { print(example5method); } } + example5() { // Create an anonymous instance of the Example5Class and call the sayIt // method on it. @@ -86,6 +94,7 @@ class Example6Class { print(instanceVariable); } } + example6() { new Example6Class().sayIt(); } @@ -96,10 +105,12 @@ class Example7Class { static sayItFromClass() { print(classVariable); } + sayItFromInstance() { print(classVariable); } } + example7() { Example7Class.sayItFromClass(); new Example7Class().sayItFromInstance(); @@ -111,7 +122,7 @@ example7() { // by default. But arrays and maps are not. They can be made constant by // declaring them "const". var example8Array = const ["Example8 const array"], - example8Map = const {"someKey": "Example8 const map"}; + example8Map = const {"someKey": "Example8 const map"}; example8() { print(example8Array[0]); print(example8Map["someKey"]); @@ -172,6 +183,7 @@ example13() { print("Example13 regexp doesn't match '${s}'"); } } + match(s1); match(s2); } @@ -190,7 +202,7 @@ example14() { } // dynamic typed null can be convert to bool - var b;// b is dynamic type + var b; // b is dynamic type b = "abc"; try { if (b) { @@ -240,9 +252,11 @@ example15() { // StringBuffer. Or you could join a string array. example16() { var sb = new StringBuffer(), a = ["a", "b", "c", "d"], e; - for (e in a) { sb.write(e); } + for (e in a) { + sb.write(e); + } print("Example16 dynamic string created with " - "StringBuffer '${sb.toString()}'"); + "StringBuffer '${sb.toString()}'"); print("Example16 join string array '${a.join()}'"); } @@ -302,11 +316,13 @@ class Example21 { set names(List<String> list) { _names = list; } + int get length => _names.length; void add(String name) { _names.add(name); } } + void example21() { Example21 o = new Example21(); o.add("c"); @@ -320,7 +336,9 @@ class Example22A { var _name = "Some Name!"; get name => _name; } + class Example22B extends Example22A {} + example22() { var o = new Example22B(); print("Example22 class inheritance '${o.name}'"); @@ -334,19 +352,21 @@ example22() { // single inheritance doesn't get in the way of reusable code. // Mixins follow the "with" statement during the class declaration. class Example23A {} + class Example23Utils { addTwo(n1, n2) { return n1 + n2; } } + class Example23B extends Example23A with Example23Utils { addThree(n1, n2, n3) { return addTwo(n1, n2) + n3; } } + example23() { - var o = new Example23B(), r1 = o.addThree(1, 2, 3), - r2 = o.addTwo(1, 2); + var o = new Example23B(), r1 = o.addThree(1, 2, 3), r2 = o.addTwo(1, 2); print("Example23 addThree(1, 2, 3) results in '${r1}'"); print("Example23 addTwo(1, 2) results in '${r2}'"); } @@ -362,12 +382,13 @@ class Example24A { } get value => _value; } + class Example24B extends Example24A { Example24B({value: "someOtherValue"}) : super(value: value); } + example24() { - var o1 = new Example24B(), - o2 = new Example24B(value: "evenMore"); + var o1 = new Example24B(), o2 = new Example24B(value: "evenMore"); print("Example24 calling super during constructor '${o1.value}'"); print("Example24 calling super during constructor '${o2.value}'"); } @@ -379,10 +400,11 @@ class Example25 { var value, anotherValue; Example25({this.value, this.anotherValue}); } + example25() { var o = new Example25(value: "a", anotherValue: "b"); print("Example25 shortcut for constructor '${o.value}' and " - "'${o.anotherValue}'"); + "'${o.anotherValue}'"); } // Named parameters are available when declared between {}. @@ -394,17 +416,19 @@ example26() { _name = name; _surname = surname; } + setConfig2(name, [surname, email]) { _name = name; _surname = surname; _email = email; } + setConfig1(surname: "Doe", name: "John"); print("Example26 name '${_name}', surname '${_surname}', " - "email '${_email}'"); + "email '${_email}'"); setConfig2("Mary", "Jane"); print("Example26 name '${_name}', surname '${_surname}', " - "email '${_email}'"); + "email '${_email}'"); } // Variables declared with final can only be set once. @@ -416,6 +440,7 @@ class Example27 { // that follows the : Example27({this.color1, color2}) : color2 = color2; } + example27() { final color = "orange", o = new Example27(color1: "lilac", color2: "white"); print("Example27 color is '${color}'"); @@ -434,6 +459,7 @@ class Example28 extends IterableBase { } get iterator => names.iterator; } + example28() { var o = new Example28(); o.forEach((name) => print("Example28 '${name}'")); @@ -459,10 +485,12 @@ example29() { callItForMe(fn()) { return fn(); } + rand() { v = new DM.Random().nextInt(50); return v; } + while (true) { print("Example29 callItForMe(rand) '${callItForMe(rand)}'"); if (v != 30) { @@ -477,8 +505,12 @@ example29() { // Parse int, convert double to int, or just keep int when dividing numbers // by using the ~/ operation. Let's play a guess game too. example30() { - var gn, tooHigh = false, - n, n2 = (2.0).toInt(), top = int.parse("123") ~/ n2, bottom = 0; + var gn, + tooHigh = false, + n, + n2 = (2.0).toInt(), + top = int.parse("123") ~/ n2, + bottom = 0; top = top ~/ 6; gn = new DM.Random().nextInt(top + 1); // +1 because nextInt top is exclusive print("Example30 Guess a number between 0 and ${top}"); @@ -488,10 +520,11 @@ example30() { } else { tooHigh = n > gn; print("Example30 Number ${n} is too " - "${tooHigh ? 'high' : 'low'}. Try again"); + "${tooHigh ? 'high' : 'low'}. Try again"); } return n == gn; } + n = (top - bottom) ~/ 2; while (!guessNumber(n)) { if (tooHigh) { @@ -503,6 +536,44 @@ example30() { } } +// Optional Positional Parameter: +// parameter will be disclosed with square bracket [ ] & square bracketed parameter are optional. +example31() { + findVolume31(int length, int breath, [int height]) { + print('length = $length, breath = $breath, height = $height'); + } + + findVolume31(10,20,30); //valid + findVolume31(10,20); //also valid +} + +// Optional Named Parameter: +// parameter will be disclosed with curly bracket { } +// curly bracketed parameter are optional. +// have to use parameter name to assign a value which separated with colan : +// in curly bracketed parameter order does not matter +// these type parameter help us to avoid confusion while passing value for a function which has many parameter. +example32() { + findVolume32(int length, int breath, {int height}) { + print('length = $length, breath = $breath, height = $height'); + } + + findVolume32(10,20,height:30);//valid & we can see the parameter name is mentioned here. + findVolume32(10,20);//also valid +} + +// Optional Default Parameter: +// same like optional named parameter in addition we can assign default value for this parameter. +// which means no value is passed this default value will be taken. +example33() { + findVolume33(int length, int breath, {int height=10}) { + print('length = $length, breath = $breath, height = $height'); + } + + findVolume33(10,20,height:30);//valid + findVolume33(10,20);//valid +} + // Programs have only one entry point in the main function. // Nothing is expected to be executed on the outer scope before a program // starts running with what's in its main function. @@ -510,12 +581,15 @@ example30() { // the program needs to startup with. main() { print("Learn Dart in 15 minutes!"); - [example1, example2, example3, example4, example5, example6, example7, - example8, example9, example10, example11, example12, example13, example14, - example15, example16, example17, example18, example19, example20, - example21, example22, example23, example24, example25, example26, - example27, example28, example29, example30 - ].forEach((ef) => ef()); + [ + example1, example2, example3, example4, example5, + example6, example7, example8, example9, example10, + example11, example12, example13, example14, example15, + example16, example17, example18, example19, example20, + example21, example22, example23, example24, example25, + example26, example27, example28, example29, + example30 // Adding this comment stops the dart formatter from putting all items on a new line + ].forEach((ef) => ef()); } ``` @@ -526,6 +600,3 @@ Dart has a comprehensive web-site. It covers API reference, tutorials, articles useful Try Dart online. [https://www.dartlang.org](https://www.dartlang.org) [https://try.dartlang.org](https://try.dartlang.org) - - - |