CODEWITHSUNDEEP
javascriptarraysif-statementfor-loop
Dribel
Dribel

Reputation: 495

If clause with multiple conditions

I seem to be lost or just seem to be confused. To simplify the problem: I want to check whether each in an array holds true and if and only if all are true it should return a specific value.

var trueArray=[true,true,true,true];

As in my code, the array can have length up to 100 elements, I can't simply check for every element but need a for loop.

for(var i=0;i<trueArray.length;i++){
   if(trueArray[i]===true)
  {
     //do something
  }
}

However, the above code does something on each step of the loop but I only want it to do something once every condition held true and not in between. Can't think of the solution at the moment?

Upvotes: 0

Views: 94

Answers (6)

JKirchartz
JKirchartz

Reputation: 18022

If it's guaranteed to be a boolean you can check if any of them are false instead of if they're all true with Array.prototype.indexOf

if(trueArray.indexOf(false) === -1) {
   // none are false, so do stuff
}

You wouldn't need to use a loop or create a function.

Upvotes: 2

Mai
Mai

Reputation: 338

You can do it like this...

var trueArray=[true, true, true, true];
var allTrue=false;
for(var i=0;i<trueArray.length;i++){
   if(trueArray[i]===false){
       allTrue=false;
       break;
   }
   else
   {
       allTrue=true;
   }
}
if(allTrue==true)
{
      // do something if all values are true
}

You must break the loop if the false value is detected.

Upvotes: 0

Born2Code
Born2Code

Reputation: 1075

You should short circuit the logic as soon as you get a false value, must answers are not getting your question because of the misleading logic you put inside the for even though you only want it done once if all values are true.

You need something like

var flag=true; for(var i =0;i

if (flag) { do something}

Upvotes: 0

Barmar
Barmar

Reputation: 780798

Use Array.prototype.every

if (trueArray.every(function(x) { return x; })) {
    //do something
}

Upvotes: 2

dotnetom
dotnetom

Reputation: 24901

Try the following code:

var currentValue = true;
for(var i=0;i<trueArray.length;i++){
     if(trueArray[i]===false){
         currentValue = false;
     }
}
if(currentValue === true){
    //do something
}

Upvotes: 0

Tyr
Tyr

Reputation: 2810

Declare a check variable who is already true and set it to false if one of your array values is false. After that, check if it's true and do something.

Example: 

var trueArray=[true,true,true,true];
var bCheckArrayVal = true;

for(var i=0;i<trueArray.length;i++){
   if(trueArray[i]===false){
     bCheckArrayVal = false;
   }

   if (bCheckArrayVal) {
      // do something if true
   } else {
      // do something if false
   }
}

Upvotes: 0

Related Questions