Definition of an array:
1 < script type = "text/javascript" > 2 // <!--declare array--> 3 // 1. First declare the length of the array, then assign the value 4 var arr = new Array( 5 ); 5 document.write ( "The length of the array is: " + arr.length + " <br/> " ); 6 var num = 4 ; 7 for ( var i = 0 ;i < arr.length;i ++){ 8 num = num + 7 ; 9 arr[i] = num; 10 } 11 document.writeln( " Array elements are: " + " <br/> " ); 12 for ( var i = 0 ;i < arr .length;i ++ ){ 13 document.writeln(arr[i]); 14 } 15 // 2. Assign 16 directly to the array var arr1 = new Array( 45 , 56 , 76 , ' sleepy ' , 78 ); 17 document.writeln( " <br/> " + " Array elements are: " + " <br/> " ); 18 for ( var i = 0 ;i < arr1.length;i ++ ){ 19 document.writeln(arr1[i]); 20 } 21 // 3. Assign 22 at the same time when declaring var arr2=[34,45,56,678,'大华']; 23 document.writeln("<br/>"+"数组元素为："+"<br/>"); 24 for(var i=0;i<arr2.length;i++){ 25 document.writeln(arr2[i]); 26 } 27 28 // Common methods of arrays 29 function Compare(num1,num2){ 30 31 return num1 - num2; 32 } 33 document.writeln( " <br/> " + "The sorted array elements are: " + " <br/> " ) ; 34 document.writeln(arr.sort(Compare)); 35 arr.reverse(); 36 document.writeln( " <br/> " + "The reversed array elements are: " + " <br/>"); 37 for ( var i = 0 ;i < arr.length;i ++ ){ 38 document.writeln(arr[i]); 39 } 40 document.writeln( " <br/> " + " Array after concatenation The elements are: " + " <br/> " ); 41 document.writeln(arr.join( " ~~ " )); 42 43 // Data type conversion 44 var num = '123 Hako would like to watch the union as soon as possible ' ; 45 var num1 = parseInt(num); 46 if (isNaN(num1)){ 47 48 document.write( " <br/> " + " This value is not a number " ); 49 } else { 50 51 document.write( " <br/> " + " This value can be converted to a number " ); 52 } 53 54 </ script >
Run the screenshot:
