Dojo/_ base/Array

Official Address: http://dojotoolkit.org/reference-guide/1.10/dojo/_base/array.html#dojo-base-array

The array module dojo is well encapsulated. If you want to call it, you must first load the module:

require(["dojo/_base/array"], function(array){  // array contains the features});

 

Indexof ()

Returned value: the position where the string appears for the first time in the array. If no value is found,-1 is returned by default.

require(["dojo/_base/array"], function(array){  array.indexOf(arrayObject, valueToFind, fromIndex, findLast);});

 

Example:

require(["dojo/_base/array", "dojo/dom", "dojo/dom-construct", "dojo/on", "dojo/domReady!"],function(array, dom, domConst, on){  var arrIndxOf = ["foo", "hoo", "zoo"];  on(dom.byId("refButton1"), "click", function(){    var position = array.indexOf(arrIndxOf, "zoo");    domConst.place(      "<p>The index of the word ‘zoo‘ within the array is " + position + "</p>",      "result1",      "after"    );  });});<div>The content of our test array is <code>["foo", "hoo", "zoo"]</code>.</div><button id="refButton1" type="button">Show the index of the word ‘zoo‘ within the array.</button><div id="result1"></div>

Lastindexof ()

Returned value: the last position of the string in the array. If no value is found,-1 is returned by default.

require(["dojo/_base/array"], function(array){  array.lastIndexOf(arrayObject, valueToFind, fromIndex);});

Example:

require(["dojo/_base/array", "dojo/dom-construct", "dojo/dom", "dojo/on", "dojo/domReady!"],function(array, domConst, dom, on){  var arrLastIndxOf = ["foo", "hoo", "zoo", "shoe", "zoo", "nuu"];  on(dom.byId("refButton2"), "click", function(){    var position = array.lastIndexOf(arrLastIndxOf, "zoo");    domConst.place(      "<p>The last index of the word ‘zoo‘ within the array is " + position + "</p>",      "result2",      "after"    );  });});<div>The content of our test array is <code>["foo", "hoo", "zoo", "shoe", "zoo", "nuu"]</code>.</div><button id="refButton2" type="button">Show the last index of the word ‘zoo‘ within the array.</button><div id="result2"></div>

Foreach ()

Traverse the array or nodelists.

require(["dojo/_base/array"], function(array){  array.forEach(arrayObject, callback, thisObject);});

The third parameter adjusts the access range of foreach.

Example:

require(["dojo/_base/array"], function(array){  var foo = {    myMethod: function(el){        console.log(el);    }  };  array.forEach(["a","b","c"],function(item){    this.myMethod(item);  }, foo);});

If you want to break this loop, you can use some ()

require(["dojo/_base/array", "dojo/dom", "dojo/on", "dojo/domReady!"],function(array, dom, on){  on(dom.byId("start"), "click", function(){    var myArray = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],        count;    // iterate ALL entries of myArray    count = 0;    array.forEach(myArray, function(entry){      count++;    });    alert("iterated " + count + " entries (forEach())"); // will show "iterated 10 entries"    // let‘s only iterate the first 4 entries of myArray    count = 0;    array.some(myArray, function(entry){      if(count >= 4){        return false;      }      count++;    });    alert("iterated "+count+" entries (some())"); // will show "iterated 4 entries"  });});<button id="start" type="button">Start Testloops</button>

Filter ()

Returned value: the result array after array filtering.

require(["dojo/_base/array"], function(array){  filteredArray = array.filter(unfilteredArray, callback, thisObject);});

Example:

require(["dojo/_base/array", "dojo/dom", "dojo/dom-construct", "dojo/on", "dojo/domReady!"],function(array, dom, domConst, on){  var arr = [    { surname: "Washington", name: "Paul" },    { surname: "Gordon", name: "Amie" },    { surname: "Meyer", name: "Sofie" },    { surname: "Jaysons", name: "Josh" },    { surname: "Washington", name: "George" },    { surname: "Doormat", name: "Amber" },    { surname: "Smith", name: "Susan" },    { surname: "Hill", name: "Strawberry" },    { surname: "Washington", name: "Dan" },    { surname: "Dojo", name: "Master" }  ];  on(dom.byId("start"), "click", function(){    var filteredArr = array.filter(arr, function(item){      return item.surname == "Washington";    });    array.forEach(filteredArr, function(item, i){      domConst.create("li", {innerHTML: i+1+". "+item.surname+", "+item.name}, "filtered-items");    });    array.forEach(arr, function(item, i){      domConst.create("li", {innerHTML: i+1+". "+item.surname+", "+item.name}, "unFiltered-items");    });  });});<button id="start" type="button">Filter array</button><br/><div style="width: 300px; float: left;">  Filtered items<br />  (only people with "Washington" as surname)  <ul id="filtered-items">  </ul></div><div style="width: 300px; float: left;">  Unfiltered items<br />  (all people are represented in the list)  <ul id="unFiltered-items">  </ul></div>

Map ()

Returned value: Another modified array.

require(["dojo/_base/array"], function(array){  array.map(arrayObject, callback, thisObject);});

Example:

require(["dojo/_base/array", "dojo/dom", "dojo/dom-construct", "dojo/on", "dojo/domReady!"],function(array, dom, domConst, on){  var arrValues = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];  on(dom.byId("button"), "click", function(){    var doubleValue = array.map(arrValues, function(item){      return item * 2;    });    array.forEach(doubleValue, function(item){      var li = domConst.create("li");      li.innerHTML = item;      dom.byId("arrValuesAfter-items").appendChild(li);    });    array.forEach(arrValues, function(item){      var li = domConst.create("li");      li.innerHTML = item;      dom.byId("arrValues-items").appendChild(li);    });  });});<button id="button" type="button">Run array.map()</button><br /><div style="width: 300px; float: left; margin-top: 10px;">  Values before running array.map()  <ul id="arrValues-items"></ul></div><div style="width: 300px; float: left; margin-top: 10px;">  Values after running array.map()  <ul id="arrValuesAfter-items"></ul></div>

Sometimes in order not to modify the original array itself, Dojo provides the dojo/_ base/lang: Clone ()

Example:

require(["dojo/_base/array", "dojo/_base/lang", "dojo/dom", "dojo/dom-construct", "dojo/on", "dojo/domReady!"],function(array, lang, dom, domConst, on){  var arrSalary = [    { surname: "Washington", name: "Paul", salary: 200 },    { surname: "Gordon", name: "Amie", salary: 350 },    { surname: "Meyer", name: "Sofie", salary: 100 },    { surname: "Jaysons", name: "Josh", salary: 2500 },    { surname: "Washington", name: "George", salary: 10 },    { surname: "Doormat", name: "Amber", salary: 320 },    { surname: "Smith", name: "Susan", salary: 3200 },    { surname: "Hill", name: "Strawberry", salary: 290 },    { surname: "Washington", name: "Dan", salary: 200 },    { surname: "Dojo", name: "Master", salary: 205 }  ];  on(dom.byId("button"), "click", function(){    var raisedSalaries = array.map(arrSalary, function(item){      var newItem = lang.clone(item);      newItem.salary += (newItem.salary/100)*10;      return newItem;    });    array.forEach(raisedSalaries, function(item, i){      var li = domConst.create("li");      li.innerHTML = i+1+". "+item.surname+", "+item.name+". New salary: "+item.salary;      dom.byId("filteredSalary-items").appendChild(li);    });    array.forEach(arrSalary, function(item, i){      var li = domConst.create("li");      li.innerHTML = i+1+". "+item.surname+", "+item.name+". Old salary: "+item.salary;      dom.byId("unFilteredSalary-items").appendChild(li);    });  });});<button id="button" type="button">Raise the salary</button><br /><div style="width: 300px; float: left; margin-top: 10px;">  Peoples‘ salaries after raise:  <ul id="filteredSalary-items"></ul></div><div style="width: 300px; float: left; margin-top: 10px;">  Peoples‘ salaries before raise:  <ul id="unFilteredSalary-items"></ul></div>

Some ()

Return Value: true or false. If one of the methods is true, true is returned. It is often used in if statements.

require(["dojo/_base/array"], function(array){  var a = array.some(arrayObject, callback, thisObject);});

Example: Check whether there is a value greater than or equal to 1,000,000.

require(["dojo/_base/array", "dojo/dom", "dojo/dom-construct", "dojo/on", "dojo/domReady!"],function(array, dom, domConst, on){  var arrIndxSome = [200000, 500000, 350000, 1000000, 75, 3];  on(dom.byId("refButton6"), "click", function(){    if(array.some(arrIndxSome, function(item){ return item >= 1000000; })){      result = ‘yes, there are‘;    }else{      result = ‘no, there are no such items‘;    }    domConst.place(      "<p>The answer is: " + result + "</p>",      "result6",      "after"    );  });});<div>The content of our test array is <code>[200000, 500000, 350000, 1000000, 75, 3]</code>.</div><button id="refButton6" type="button">Are there some items >=1000000 within the array?</button><div id="result6"></div>

Every ()

Return Value: true or false. True is returned only when each item in the method returns true. It is often used in if statements.

require(["dojo/_base/array"], function(array){  array.every(arrayObject, callback, thisObject);});

Example: Check whether each item is greater than 3000

require(["dojo/_base/array", "dojo/dom", "dojo/dom-construct", "dojo/on", "dojo/domReady!"],function(array, dom, domConst, on){  var arrIndxEvery = [    { month: "january", income: 2000 },    { month: "february", income: 3200 },    { month: "march", income: 2100 }  ];  on(dom.byId("refButton7"), "click", function(){    if(array.every(arrIndxEvery , function(item){ return item.income >= 3000; })){      result = "yes, all income >= 3000";    }else{      result = "no, not all income >= 3000";    }    domConst.place(      "<p>The answer is: " + result + "</p>",      "result7",      "after"    );  });});<div>The content of our test array is <code>[{ month: "january", income: 2000 }, { month: "february", income: 3200 }, { month: "march", income: 2100 }]</code>.</div><button id="refButton7" type="button">Is the client allowed to get the credit?</button><div id="result7"></div>