Difference between == and ===

    // Equality in JS
    // What is the difference between == and ===
    // The negative versions are != and !==
    
    let a, b, obj1, obj2, copy1, copy2, html1, html2;
    a = 5;
    b = 5;
    
    if(a == b){
          console.log('a b are double equal');			// returns true
    } else {
          console.log('a b are not double equal');
    }    
    
    if(a === b){
          console.log('a b are triple equal');			// returns true
    } else {
          console.log('a b are not triple equal');
    }    
    
    obj1 = {prop: 'value'};
    obj2 = {prop: 'value');
    
    if(obj1 == obj2){
          console.log('obj1 obj2 are double equal');
    } else {
          console.log('obj1 obj2 are not double equal');   	// returns false – even though both objects look the same!
    }    
    
    if(obj1 === obj2){
          console.log('obj1 obj2 are triple equal');
    } else {
          console.log('obj1 obj2 are not triple equal');	// returns false, not the same object
    }    
    
    copy1 = obj1;
    copy2 = obj1;
    
    if(copy1 == copy2){
          console.log('copy1 copy2 are double equal');		// returns true
    } else {
          console.log('copy1 copy2 are not double equal');   	
    }    
    
    if(copy1 === copy2){
          console.log('copy1 copy2 are triple equal');		// returns true
    } else {
          console.log('copy1 copy2 are not triple equal');	
    }    
    
    html1 = document.querySelector('h1');
    html2 = document.querySelector('h1');
    
    if(html1 == html2){
          console.log('html1 html2 are double equal');		// returns true
    } else {
          console.log('html1 html2 are not double equal');   	
    }    
    
    if(html1 === copy2){
          console.log('html1 html2 are triple equal');		// returns true
    } else {
          console.log('html1 html2 are not triple equal');	
    }