string - 如何在powershell中从字符串中获取十进制数？

Question

1. 我有一个包含十进制值的字符串（例如'good1432.28morning to you'）
2. 我需要 从字符串中提取1432.28并将其转换为十进制

Answer 1

这可以通过多种方式完成，在 stackoverflow 中找不到完全相同的问题/解决方案，所以这里有一个对我有用的快速解决方案。

Function get-Decimal-From-String 
{
    # Function receives string containing decimal
 param([String]$myString)

    # Will keep only decimal - can be extended / modified for special needs
$myString = $myString -replace "[^\d*\.?\d*$/]" , ''

    # Convert to Decimal 
[Decimal]$myString

}

调用函数

$x = get-Decimal-From-String 'good1432.28morning to you'

结果

1432.28

Answer 2

("good1432.28morning to you" -split "\.")[1]

(1557.18 -split "\.")[1]

Answer 3

其他解决方案：

-join ('good143.28morning to you' -split '' | where {$_ -ge '0' -and $_ -le '9' -or $_ -eq '.'})

Answer 4

另一种选择：

function Get-Decimal-From-String {
    # Function receives string containing decimal
    param([String]$myString)

    if ($myString -match '(\d+(?:\.\d+)?)') { [decimal]$matches[1] } else { [decimal]::Zero }
}

正则表达式详细信息

(               Match the regular expression below and capture its match into backreference number 1
   \d           Match a single digit 0..9
      +         Between one and unlimited times, as many times as possible, giving back as needed (greedy)
   (?:          Match the regular expression below
      \.        Match the character “.” literally
      \d        Match a single digit 0..9
         +      Between one and unlimited times, as many times as possible, giving back as needed (greedy)
   )?           Between zero and one times, as many times as possible, giving back as needed (greedy)
)