Variable HELP!

[XHTMLboy]

Hi, i have just started to learn abit about javascript, but i came to a part in a book which i coulden't get my head around. It would be nice if someone could just explane this as easy as possible. I think i get it, it's just in the code what does var answer do. and how does alert(15 / 10); work.

 var firstNumber = 15;		var secondNumber = 10;		var answer; 		answer = 15 / 10;		alert(answer); 		alert(15 / 10); 		answer = firstNumber / secondNumber;		alert(answer);

[ShadowMage]

Hi, i have just started to learn abit about javascript, but i came to a part in a book which i coulden't get my head around. It would be nice if someone could just explane this as easy as possible. I think i get it, it's just in the code what does var answer do. and how does alert(15 / 10); work.

var answer; just declares a variable named answer. It does not initialize (assign a value) to it yet.alert(15 / 10); just alerts the value of 15 divided by 10 (which is 1.5). Anything inside the parenthesis is evaluated first then a message box is appears showing the return value of whatever expressions/statements were inside the parenthesis.

[XHTMLboy]

var answer; just declares a variable named answer. It does not initialize (assign a value) to it yet.alert(15 / 10); just alerts the value of 15 divided by 10 (which is 1.5). Anything inside the parenthesis is evaluated first then a message box is appears showing the return value of whatever expressions/statements were inside the parenthesis.

Oh ok, so alert(10 /15); does not need a varable. And var answer; holds what?

[thescientist]

Oh ok, so alert(10 /15); does not need a varable. And var answer; holds what?

well, first it holds nothing, as ShadowMage explained. Then it is assigned the value of 15/10. Then it is assigned the value of firstNumber/secondNumber, which is also 15/10, which yields the same value as 15/10.

[aspnetguy]

var firstNumber = 15;  //this variable is declared and set to a value of 15var secondNumber = 10; //this variable is declared and set to a value of 10var answer; //this variable is declared but no value is assigned to it. It currently is null or undefinedanswer = 15 / 10; //the expression is evaluated and a value of 1.5 is assigned to the variablealert(answer); //alerts the value of the variable answer which is currently 1.5alert(15 / 10); //evaluates the expression and alerts the result - 1.5answer = firstNumber / secondNumber; // evaluates the expression and the values of the variables used (15/10) and assigns the result to answeralert(answer); //alerts the current value of answer which is still 1.5

[XHTMLboy]

var firstNumber = 15;  //this variable is declared and set to a value of 15var secondNumber = 10; //this variable is declared and set to a value of 10var answer; //this variable is declared but no value is assigned to it. It currently is null or undefinedanswer = 15 / 10; //the expression is evaluated and a value of 1.5 is assigned to the variablealert(answer); //alerts the value of the variable answer which is currently 1.5alert(15 / 10); //evaluates the expression and alerts the result - 1.5answer = firstNumber / secondNumber; // evaluates the expression and the values of the variables used (15/10) and assigns the result to answeralert(answer); //alerts the current value of answer which is still 1.5

thankyou for your help