Usage:

The JavaScript Array every() method is used to check if all elements in an array pass a test provided by a specified function.

Example:

function isPalindrome( element ){
    let numStr = element.toString( );
    let result = numStr.split( '' ).reverse( ).join( '' );
    return numStr === result;
}

let arr = [ 121, 1331, 242, 535, 747 ];

let value = arr.every( isPalindrome );
console.log( value );

Output: