Javascript String Type check if a variable is a string

let a = String("I'm a String Object"); 
let b = "I'm a string literal"; 
let c = 7; //from ww  w .j a  v a2 s.  c  om
let d = new Date(); 

if ( typeof a === 'string' ) { 
    console.log("a is a String"); 
} else { 
    console.log("a is not a String"); 
} 

if ( typeof b === 'string' ) { 
    console.log("b is a String"); 
} else { 
    console.log("b is not a String"); 
} 

if ( typeof c === 'string' ) { 
    console.log("c is a String"); 
} else { 
    console.log("c is not a String"); 
} 

if ( typeof d === 'string' ) { 
    console.log("d is a String"); 
} else { 
    console.log("d is not a String"); 
}