The detection method of JavaScript palindrome and class name

palindrome * *

"123" changed to "123321"

"abc321" changed to "ABCD321123CBA"

function fn (str) {

Convert string to string array (with or without spaces)

  var arr=str.split (');

  Console.log (arr);

Reverses the order of string arrays

  var reversearr=arr.reverse ();

  Console.log (Reversearr);

Stitching arrays of inverted order into strings (with or without spaces)

  var reversestr=reversearr.join ("");

  Console.log (REVERSESTR);

Stitch the original string together with the inverted string to get the result

  return str+reversestr;

  //Shorthand

  //returen Str+str.split (""). Reverse.join ("");

}

Console.log (FN ("This was an apple");

Console.log (FN ("abc321"));

Detecting class names

function  Checkclass (A, b) {

  //Get class an array group

  var allclass = A.split (");

  Console.log (Allclass);

Determines whether the value of B has occurred in the array

If it does not appear (with: true, no: false)

  var i=0;

  var result=false;

For  (; i<allclass.length;i++) {

  if (allclass[i]===b) {

If these two values are equal, the value of an item in the array is equal to B, and the previous assumption is wrong.

  result=true;

Break  ;

  }

  }

  return result;

}

The IndexOf method, if not found, returns-1, if found, returns the angle label of the array

  if (allclass.indexof (b) = = = 1) {

  return false;

  } else {

  return true;

  }

}

Console.log (Checkclass ("Name right", "right"));

Console.log (Checkclass ("Name right", "left");

var obj1 = {

A:10,

B:20

};

?

var obj2 = obj1;

?

obj1.a = 30;

?

Console.log (obj2.a);

Console.log (obj1.a);

?

Reference type: When assigning data of a reference type to a variable, it does not assign the data itself to the variable, but instead assigns the reference to the variable

?

var arr = [1, 2, 3];

var arr2 = arr;

ARR[1] = 10;

Console.log (ARR2);

The detection method of JavaScript palindrome and class name