JavaScript Basics--arrays, string manipulation, math functions

How to manipulate data:

1 vararr = [1,2,3,4,5];2 3Arr.push (6,7);//You can add a sequence (1+) to the last digit of the array, and return the length of the array. 4 5Arr.pop ();//deletes the last digit of the array. and returns the contents of that array. 6 7Arr.shift ();//deletes the No. 0 bit of the array and returns the contents of that array. 8 9Arr.unshift ( -1,0);//adds a sequence of numbers from the No. 0 bit of the array and returns the length of the array. Ten  OneArr.join (");//Separates each column array by the specified symbol or by a non-set symbol (an empty string). 

Ways to manipulate strings:

Implement push, pop, shift, and unshift methods with splice

1    vararr = [3,2];2    varArropts= (function(){3 4     functionOarray (arr) {5 6         if(Array.isarray (arr)) {7             return true;8}Else{9             return false;Ten         } One  A         } -     functionOpush (arr) { -  the         if(!Oarray (arr)) { -             return"Not an array! "; -         } -          +          for(vari=1;i<arguments.length;i++){ -Arr.splice (arr.length,0, Arguments[i]); +         } A          at         returnarr.length; -     } -  -     functionOPop (arr) { -          -         if(!Oarray (arr)) { in             return"Not an array! "; -         } to          +         returnArr.splice (arr.length-1,1) [0]; -     } the  *     functionOunshift (arr) { $        if(!Oarray (arr)) {Panax Notoginseng             return"Not an array! "; -         } the         if(arguments.length>=2){ +              for(vari = arguments.length-1;i>0;i--){ AArr.splice (0,0, Arguments[i]); the             } +         } -         returnarr.length; $     } $  -     functionOshift (arr) { -         if(!Oarray (arr)) { the             return"Not an array! "; -         }Wuyi         returnArr.splice (0,1) [0]; the     } -  Wu     return { - Opush:opush, About Opop:opop, $ Ounshift:ounshift, - Oshift:oshift -     } -  A})();

Stitching string Operations:

1 varProd = {name: ' Ladies ', styles:[' cropped ', ' Winter ', ' Spring '] };2 3 functionGETTPL (data) {4 5 varHTML =[]; Html.push (' <dl class= ' product ' > ');6 7Html.push (' <dt> ' +data.name+ ' </dt> ');8 9  for(varI =0;i<data.styles.length;i++){Ten  OneHtml.push (' <dd> ' +data.styles[i]+ ' </dd> '); A  - } -  theHtml.push (' </dl> ')); -  - returnHtml.join (' '); -  + } -  + varresult =gettpl (prod); A  atConsole.log (result);//

Write a find function that implements the following functions

1 vararr = [' Test ', 2, 1.5,false];2 functionFind (Arr,ele) {3      for(vari=0;i<arr.length;i++){4         if(Arr[i] = = =ele) {5             returni;6         }   7     }8     return-1;9 }TenFind (arr, "test")//0 OneFind (arr, 2)//1 AFind (arr, 0)//-1

Write a function to filter the array, not the elements of the number.

1 varArr=["A", 1, "B", 2];2 3 functionFilternumeric (arr) {4     varFooarr = [];5      for(vari=0;i<arr.length;i++){6         if(typeofArr[i] = = = ' Number '){7 Fooarr.push (Arr[i]);8         }9     }Ten     returnFooarr; One}

JavaScript Basics--arrays, string manipulation, math functions