I am new to JavaScript. I am trying to make an exercise program which generates a random number between a min and a max value. I am facing an issue in the program below. var2 + min
is not working correctly. If I replace variable min with the actual value, then it works. What am I doing wrong?
var var1=Math.random()
var min = prompt("Enter Min value:")
var max = prompt("Enter max value:")
alert("min is "+min+" max is "+max)
var var2=var1*(max-min)
var var3=var2+min
var var4=Math.floor(var3)
alert("var1= "+var1+" var2= "+var2+" var3= "+var3+" Var4 "+var4)
Use:
var min = parseInt(prompt("Enter Min value:"), 10);
var max = parseInt(prompt("Enter max value:"), 10);
The problem is that these variables contain strings, so the expressions containing +
are performing string concatenation rather than number addition.
And while you're learning, get in the habit of ending statements with ;
. Javascript is lax about requiring this, but you should be explicit about it -- the rules for when semicolon can be omitted are a bit arcane.
var1
, var2
, var3
, etc. are not good variable names. Don't use them.
Your code isn't working because prompt
returns a string. 1 - "2"
is -1
, but 1 + "2"
is "12"
, as the addition operator is used for string concatenation.
Parse the strings into integers:
var min = parseInt(prompt("Enter Min value:"), 10);
prompt
returns a string
so you need to convert min
and max
to a number
:
var min = Number(prompt("Enter Min value:"));
var max = Number(prompt("Enter max value:"));
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