Упр №3, стр 109

index.js

var input = "javascript is awesome";
var output = "";

for(var i=0; i < input.length; i++){

	if(input[i] === "a"){
		output += "4";
	}else if(input[i] === "e"){
		output += "3";
	}
	else if(input[i] === "i"){
		output += "1";
	}
	else if(input[i] === "o"){
		output += "0";
	}
	else{
		output += input[i]; // output = output + input[i];
	}
}
console.log(output);