Math.max not returning either number being compared

Question

Below is a simply Math.max statement I'm trying to use in my jQuery app, along with the methods being called.

    guaranteedEoy: function() {
        return this.fixedAllocation() * (1 + (this.attributes.fixedRate / 100)) * Math.pow(1, 6);
    },

    contractVal: function (value) {
        value = parseFloat(value).toFixed(2);
        console.log(value);
        console.log(this.guaranteedEoy());
        console.log(parseFloat(this.guaranteedEoy()) + parseFloat(value));
        console.log(this.attributes.purchasePayment * Math.pow(1.01, 7));
        console.log(Math.max((this.attributes.purchasePayment * Math.pow(1.01, 7)), (this.guaranteedEoy() + value)));
        console.log('   ');
        return Math.max((this.attributes.purchasePayment * Math.pow(1.01, 7)), (this.guaranteedEoy() + value));
    },

I put the console.log statements in there because the number being returned from the Math.max function is exponentially larger than either number it is supposed to be comparing. To illustrate here's a screen print of the console readouts from above:

enter image description here

To simplify here are the values each console readout correspond to

Value: 64000.00
this.guaranteedEoy(): 37008
this.guaranteedEoy() + value: 101008
this.attributes.purchasePayment * Math.pow(1.01, 7): 107213.53521070098
Math.max((this.attributes.purchasePayment * Math.pow(1.01, 7)), (this.guaranteedEoy() + value)): 370086400

So basically the Math.max statement reads

Math.max(107213.53521070098, 101008)

However for some reason it is returning a value of 370086400.

`toFixed` returns a string. Why are you even using it? Do you just want to round the value? — Felix Kling, Sep 17 '14 at 18:56
This question does not seem to have anything to do with jQuery — Bergi, Sep 17 '14 at 19:00

Regent · Accepted Answer · 2014-09-17T19:00:42.650

370086400 is concatenation of mentioned values 37008 and 64000.

It should be:

console.log(Math.max((this.attributes.purchasePayment * Math.pow(1.01, 7)),
        (parseFloat(this.guaranteedEoy()) + parseFloat(value))));

Use parseFloat once more to avoid string concatenation (which is occured).

Edit: it looks like value is the String (due to .toFixed()), while this.guaranteedEoy() returns Number. So it is possible that parseFloat only for value will be enough.

score 1 · Answer 2 · edited May 23 '17 at 10:26

1

toFixed returns a string, so this.guaranteedEoy() + value, performs string concatenation. If you just want to round the value to two decimal places, see Round to at most 2 decimal places (only if necessary).

edited May 23 '17 at 10:26

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answered Sep 17 '14 at 18:58

Felix Kling

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Math.max not returning either number being compared

2 Answers2