first day of homework on Project Euler

Project Euler 1

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+function sum(array){
+    var val = 0
+    for (i = 0; i < array.length; i++){
+    val = val + array[i]
+    }
+    return val
+}
+
+
+function Euler3and5(highnumber){
+   var multiples = []
+       for (i = highnumber; i > 0; i--){
+        if (i % 3 === 0 || i % 5 === 0){
+        multiples.push(i)
+        }
+    }
+    return multiples
+}
+
+sum(Euler3and5(1000))

Project Euler 1.1

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+
+function Euler3and5(highnumber){
+    var sum = 0
+    for (i = 0; i <= highnumber ; i++){
+        if (i % 3 === 0 || i % 5 === 0){
+        sum = sum + i
+    }
+        }
+return sum    
+}
+
+Euler3and5(1000)

Project Euler 1.2

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+// write a function that takes a number and returns true if it is a multiple of 3 or 5
+
+function Euler3or5(number){
+    if (number % 3 === 0 || number % 5 === 0){
+        return true
+    }
+    else 
+        return false
+}
+
+Euler3or5(4)
+
+
+// even more elegant version:
+
+function Euler3or5(number){
+    return (number % 3 === 0 || number % 5 === 0)
+}
+
+Euler3or5(7) 

Project Euler 2 (even fibonacci)

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+function evenfib(maxvalue){
+    var a = [1, 1]
+    var b = 0
+for (i = 1; a[i] < 4000000; i++){
+    b = a[i-1] + a[i]
+    a.push(b)
+    }
+var total = 0
+for (i = 0; i < a.length; i++){
+    if (a[i] % 2 === 0)
+    total = total + a[i];
+}
+    return total
+}
+evenfib(46)
+
+    // returns 4,613,732
+
+
+// alternate method done with Daf below...
+
+function evenfib(limit){
+    var a = 1
+    var b = 1
+    var discard = 0
+    var total = 1
+while(b < limit){
+    discard = a
+    a = b
+    b = a + discard
+    if (b % 2 === 0){
+    total = total + b
+    }
+}
+return total
+}
+evenfib(4000000)
+
+    // returns 4,613,732