String to Float64: multiple-value strconv.ParseFlo

问题:

I have an array of STRING slices like this:

[[header1 header2 startdate enddate header3 header4] 
[item1 100 01/01/2017 02/01/2017 5343340.56343 3.77252223956] 
[item2 554 01/01/2017 02/01/2017 22139.461201388 17.232284405]]

Keep in mind that the array keeps on increasing. I am just posting a sample array.

Now I converted some of the float numbers to string so that I could append it to the string slices. However, I need to do some math with those numbers. I want to add the string number(5343340.56343) from the 2nd slice to 3rd string number (22139.461201388). Same thing with the other 2 float numbers in each slices. To do that, I need to first convert them to float64. After getting the sum, I will need to convert them back to string so I can append it to my slice which I will figure out how to do.

To convert the string item to float64, here's what I have:

for _, i := range data[1:] {
    if i[0] == "item1" {
        j := strconv.ParseFloat(i[4], 64)


    }
    if i[0] == "item2" {
        k := strconv.ParseFloat(i[4], 64)
    }
    sum := j + k
}

This gives an error: multiple-value strconv.ParseFloat() in single-value context So my question is:

1. How can I convert the string value to Float64.

2. Optional: Any suggestions on how I can add the 2 float numbers from each slice?

Any help is appreciated!

回答1:

The error you are getting is because the function ParseFloat returns two arguments and you are ignoring the second.

j, err := strconv.ParseFloat(i[4], 64)
if err != nil {
  // insert error handling here
}
(...)

Try to always check the function's signature in godocs before using it.