英文:
String to Float64: multiple-value strconv.ParseFloat() in single-value context
问题
我有一个类似这样的字符串切片数组：
[[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]]
请注意，数组会不断增长，我只是展示了一个示例数组。
现在，我将其中一些浮点数转换为字符串，以便将其附加到字符串切片上。然而，我需要对这些数字进行一些数学运算。我想将第二个切片中的字符串数字(5343340.56343)与第三个字符串数字(22139.461201388)相加。对于每个切片中的其他两个浮点数也是同样的操作。为了实现这一点，我首先需要将它们转换为float64类型。在得到总和之后，我需要将它们再次转换为字符串，以便将其附加到我的切片中（我将找出如何实现这一点）。
要将字符串项转换为float64类型，我有以下代码：
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
}
这会报错：multiple-value strconv.ParseFloat() in single-value context
所以我的问题是：
-
如何将字符串值转换为Float64类型。
-
可选：有关如何将每个切片中的两个浮点数相加的建议？
感谢任何帮助！
英文:
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:
-
How can I convert the string value to Float64.
-
Optional: Any suggestions on how I can add the 2 float numbers from each slice?
Any help is appreciated!
答案1
得分: 15
你遇到的错误是因为ParseFloat函数返回两个参数，而你忽略了第二个参数。
j, err := strconv.ParseFloat(i[4], 64)
if err != nil {
// 在这里处理错误
}
(...)
在使用之前，尝试始终在godocs中检查函数的签名。
英文:
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.
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