array in javascript
Array 1. sort & reverse e.g. : var a2=[10,2,3,1,7]; a2.reverse();// 7,1,3,2,10 a2.sort();//1,10,2,3,7 function compare(value1,value2){ if(value1<value2){return -1;} else if(value1>value2){return 1;} else{return 0;} } a2.sort(compare);// 1,2,3,7,10 function getType(obj){ let type= typeof obj; if(type!=='object'){return type;} return Object.prototype.toString.call(obj).replace(/^\[object (\S+)\]$/,'$1'); // [object Number] } var x = 15 * 5; getType(x); // Number