I am writing a small script in powershell and want to build a variable in a particular format.
$name="abc"
$json = '{\"name\":\"$name\",\"projectId\":\"10034\"}'
$json
when I am printing the value the value appears to be -
{\"name\":\"$name\",\"projectId\":\"10034\"}
I want to the output to be -
{\"name\":\"abc\",\"projectId\":\"10034\"}
How can we place the variable value inside ""(double quotes) in this case.
If you want string interpolation, you have to use double quotes. For using double quotes inside double quotes , you have to escape them with `(backquote).
$name="abc"
$json = "{\`"name\`":\`"$name\`",\`"projectId\`":\`"10034\`"}"
$json
The output is:
{\"name\":\"abc\",\"projectId\":\"10034\"}
Related
I have a string that I want to insert dynamically a variable. Ex;
$tag = '{"number" = "5", "application" = "test","color" = "blue", "class" = "Java"}'
I want to accomplish:
$mynumber= 2
$tag = '{"number" = "$($mynumber)", "application" = "test","color" = "blue", "class" = "Java"}'
What I want is to have the variable inserted on the string, But it is not going through. I guess the '' sets all as a string. Any recomendations on how should I approach this?
thanks!
powershell test and trial and error. Also Google.
The reason your current attempt doesn't work is that single-quoted (') string literals in PowerShell are verbatim strings - no attempt will be made at expanding subexpression pipelines or variable expressions.
If you want an expandable string literal without having to escape all the double-quotes (") contained in the string itself, use a here-string:
$mynumber = 2
$tag = #"
{"number" = "$($mynumber)", "application" = "test","color" = "blue", "class" = "Java"}
"#
To add to Mathias' helpful answer:
Mistakenly expecting string interpolation inside '...' strings (as opposed to inside "...") has come up many times before, and questions such as yours are often closed as a duplicate of this post.
However, your question is worth answering separately, because:
Your use case introduces a follow-up problem, namely that embedded " characters cannot be used as-is inside "...".
More generally, the linked post is in the context of argument-passing, where additional rules apply.
Note: Some links below are to the relevant sections of the conceptual about_Quoting_Rules help topic.
In PowerShell:
only "..." strings (double-quoted, called expandable strings) perform string interpolation, i.e. expansion of variable values (e.g. "... $var" and subexpressions (e.g., "... $($var.Prop)")
not '...' strings (single-quoted, called verbatim strings), whose values are used verbatim (literally).
With "...", if the string value itself contains " chars.:
either escape them as `" or ""
E.g., with `"; note that while use of $(...), the subexpression operator never hurts (e.g. $($mynumber)), it isn't necessary with stand-alone variable references such as $mynumber:
$mynumber= 2
$tag = "{`"number`" = `"$mynumber`", `"application`" = `"test`",`"color`" = `"blue`", `"class`" = `"Java`"}"
Similarly, if you want to selectively suppress string interpolation, escape $ as `$
# Note the ` before the first $mynumber.
# -> '$mynumber = 2'
$mynumber = 2; "`$mynumber` = $mynumber"
See the conceptual about_Special_Characters help topic for info on escaping and escape sequences.
If you need to embed ' inside '...', use '', or use a (single-quoted) here-string (see next).
or use a double-quoted here-string instead (#"<newline>...<newline>"#):
See Mathias' answer, but generally note the strict, multiline syntax of here-strings:
Nothing (except whitespace) must follow the opening delimiter on the same line (#" / #')
The closing delimiter ("# / '#) must be at the very start of the line - not even whitespace may come before it.
Related answers:
Overview of PowerShell's expandable strings
Overview of all forms of string literals in PowerShell
When passing strings as command arguments, they are situationally implicitly treated like expandable strings (i.e. as if they were "..."-enclosed); e.g.
Write-Output $HOME\projects - see this answer.
Alternatives to string interpolation:
Situationally, other approaches to constructing a string dynamically can be useful:
Use a (verbatim) template string with placeholders, with -f, the format operator:
$mynumber= 2
# {0} is the placeholder for the first RHS operand ({1} for the 2nd, ...)
'"number" = "{0}", ...' -f $mynumber # -> "number" = "2", ...
Use simple string concatenation with the + operator:
$mynumber= 2
'"number" = "' + $mynumber + '", ...' # -> "number" = "2", ...
I have a string that I want to insert dynamically a variable. Ex;
$tag = '{"number" = "5", "application" = "test","color" = "blue", "class" = "Java"}'
I want to accomplish:
$mynumber= 2
$tag = '{"number" = "$($mynumber)", "application" = "test","color" = "blue", "class" = "Java"}'
What I want is to have the variable inserted on the string, But it is not going through. I guess the '' sets all as a string. Any recomendations on how should I approach this?
thanks!
powershell test and trial and error. Also Google.
The reason your current attempt doesn't work is that single-quoted (') string literals in PowerShell are verbatim strings - no attempt will be made at expanding subexpression pipelines or variable expressions.
If you want an expandable string literal without having to escape all the double-quotes (") contained in the string itself, use a here-string:
$mynumber = 2
$tag = #"
{"number" = "$($mynumber)", "application" = "test","color" = "blue", "class" = "Java"}
"#
To add to Mathias' helpful answer:
Mistakenly expecting string interpolation inside '...' strings (as opposed to inside "...") has come up many times before, and questions such as yours are often closed as a duplicate of this post.
However, your question is worth answering separately, because:
Your use case introduces a follow-up problem, namely that embedded " characters cannot be used as-is inside "...".
More generally, the linked post is in the context of argument-passing, where additional rules apply.
Note: Some links below are to the relevant sections of the conceptual about_Quoting_Rules help topic.
In PowerShell:
only "..." strings (double-quoted, called expandable strings) perform string interpolation, i.e. expansion of variable values (e.g. "... $var" and subexpressions (e.g., "... $($var.Prop)")
not '...' strings (single-quoted, called verbatim strings), whose values are used verbatim (literally).
With "...", if the string value itself contains " chars.:
either escape them as `" or ""
E.g., with `"; note that while use of $(...), the subexpression operator never hurts (e.g. $($mynumber)), it isn't necessary with stand-alone variable references such as $mynumber:
$mynumber= 2
$tag = "{`"number`" = `"$mynumber`", `"application`" = `"test`",`"color`" = `"blue`", `"class`" = `"Java`"}"
Similarly, if you want to selectively suppress string interpolation, escape $ as `$
# Note the ` before the first $mynumber.
# -> '$mynumber = 2'
$mynumber = 2; "`$mynumber` = $mynumber"
See the conceptual about_Special_Characters help topic for info on escaping and escape sequences.
If you need to embed ' inside '...', use '', or use a (single-quoted) here-string (see next).
or use a double-quoted here-string instead (#"<newline>...<newline>"#):
See Mathias' answer, but generally note the strict, multiline syntax of here-strings:
Nothing (except whitespace) must follow the opening delimiter on the same line (#" / #')
The closing delimiter ("# / '#) must be at the very start of the line - not even whitespace may come before it.
Related answers:
Overview of PowerShell's expandable strings
Overview of all forms of string literals in PowerShell
When passing strings as command arguments, they are situationally implicitly treated like expandable strings (i.e. as if they were "..."-enclosed); e.g.
Write-Output $HOME\projects - see this answer.
Alternatives to string interpolation:
Situationally, other approaches to constructing a string dynamically can be useful:
Use a (verbatim) template string with placeholders, with -f, the format operator:
$mynumber= 2
# {0} is the placeholder for the first RHS operand ({1} for the 2nd, ...)
'"number" = "{0}", ...' -f $mynumber # -> "number" = "2", ...
Use simple string concatenation with the + operator:
$mynumber= 2
'"number" = "' + $mynumber + '", ...' # -> "number" = "2", ...
I want to save a string with a skeletton and a few variables in there to use it later.
My string:
$moddeduserdata = ("{"Id":$userid,"Timestamp":"$timestamp","FirstName":"$numberout","LastName":"$numberout","CallId":"$numberout"}")
What I want is the following output:
{"Id":261,"Timestamp":"AAAAAAAJ1KM=","FirstName":"5503","LastName":"5503","CallId": "5503"}
so this results in the error:
"unexpected token"
I also tried with ' ' instead of " " but then it just saves the line without putting in my variables.
You're trying to embed verbatim " characters in a double-quoted string ("..."), so you must escape them as `" ("" works too):
$moddeduserdata = "{`"Id`":$userid,`"Timestamp`":`"$timestamp`",`"FirstName`":`"$numberout`",`"LastName`":`"$numberout`",`"CallId`":`"$numberout`"}"
While single-quoted strings ('...') allow you to embed " chars. as-is (no need for escaping), they do not perform the string interpolation (expansion of embedded variable references) you need.
For more information about PowerShell string literals, see the bottom section of this answer.
Or make an object then convert it to compressed json:
$userid,$timestamp,$numberout,$numberout,$numberout = echo 261 AAAAAAAJ1KM 5503 5503 5503
[pscustomobject]#{Id=$userid;Timestamp=$timestamp;FirstName=$numberout;
LastName=$numberout;CallId=$numberout} | convertto-json -compress
{"Id":261,"Timestamp":"AAAAAAAJ1KM=","FirstName":"5503","LastName":"5503","CallId":"5503"}
I have a powershell script which calls another powershell file passing a string argument.
param (
[string]$strVal = "Hello World"
)
$params = #{
message = "$strVal"
}
$sb = [scriptblock]::create(".{$(get-content $ps1file -Raw)} $(&{$args} #params)")
Somehow the script passes message variable without double quotes so the powershell file receives only the first part of the message variable (before space) i.e. "Hello".
How can I pass the strVal variable with space (i.e. "Hello World")?
A double quote pair signals PowerShell to perform string expansion. If you want double quotes to output literally, you need to escape them (prevent expansion) or surround them with single quotes. However, a single quote pair signals PowerShell to treat everything inside literally so your variables will not interpolate. Given the situation, you want string expansion, variable interpolation, and literal double quotes.
You can do the following:
# Double Double Quote Escape
#{message = """$strVal"""}
Name Value
---- -----
message "Hello World"
# Backtick Escape
#{message = "`"$strVal`""}
Name Value
---- -----
message "Hello World"
Quote resolution works from left to right, which means the leftmost quote type takes precedence. So '"$strVal"' will just print everything literally due to the outside single quote pair. "'$strVal'" will print single quotes and the value of $strVal.
I have
myVar.value = 123521#machine OK
now I'm using this variable with system command as it's an argument passed to a binary .exe
so I have to add quotes to myVar.value as it caontains spaces
I tried :
'''myVar.value''' but this will give 'myVar.value', whereas I just want to have the result equal to "123521#machine OK"
how could I use the quotes in this case ?
Try this:
x = ['"' myVar.value '"']
I think you can use double quote characters within strings demarcated by single quotes. Within a string demarcated by single quotes characters by doubling up:
x = ['''' myVar.value '''']