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POJava - Most efficient way to convert string to double
 

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  1. POJava - Most efficient way to convert string to double
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    <p>Hi I am reading from a text file and saving each line (split by a comma) into an array. The only problem is that most of the elements in the array are double values where as two elements are strings. As a result of this I had to make the array a String[] array. Due to this, whenever I want to perform some equations on the double values in the array, I have to first parse them as a double value. I am literally running 1000+ iterations of these equations, therefore my code is constantly parsing the strings into a double. This is a costly way which is slowing down my program. Is there a better way I can convert the values from the string array to double values or is there a better approach I should take when saving the lines from the text file? Thanks</p> <p>Here is what one of the arrays looks like after I have read from the text file:</p> <pre><code>String[] details = {"24.9", "100.0", "19.2" , "82.0", "Harry", "Smith", "45.0"}; </code></pre> <p>I now need to multiply the first 2 elements and add that to the sum of the 3rd, 4th and 7th elements. In other words I am only using the numerical elements (that are ofcourse saved as strings)</p> <pre><code>double score = (Double.parseDouble(details[0]) * Double.parseDouble(details[1])) + Double.parseDouble(details[2]) + Double.parseDouble(details[3]) + Double.parseDouble(details[6]); </code></pre> <p>I have to do this for every single line in the text file (1000+ lines). As a result of this my program is running very slowly. Is there a better way I can convert the string values into a double? or is there a better way I should go about storing them in the first place?</p> <p>EDIT: I have used profiler to check which part of the code is the slowest and it is indeed the code that I have shown above</p>
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    1. COWhy not just convert them **once**, and store the results?
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    2. COCalling `Double.parseDouble()` 5000 times isn't going to make your program run very slowly.
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    3. CO@OliCharlesworth - Every line is different. So different values are involved
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