how to write less than equal to in javascript code example

Example 1: javascript compare number to string

let string = "1";
let number = 1;
if (parseInt(string) === number){
  	// STRING AND NUMBER MATCHES
}
if (string == number){
  // STRING AND NUMBER MATCHES ALSO BECAUSE == instead of ===, means it won't compare datasets, only the content
}

Example 2: javascript less than but greater than

let X = 4
let Y = 5
let Z = 8

if (Y < Z && Y > X) {
    console.log(`Y is less than Z but greater than X, or mathematically
	'X < Y < Z' or 'Z > Y > X'
	`);
}

Example 3: less than equal to in javascript

| <= | less than or equal to |	x <= 8 | true |

Example 4: javascript not equal

0 !== "0"
0 !== 0