Mastering Windows PowerShell Scripting - Third Edition

Addition operators

The addition operator may be used to add numeric values. For example, the simple addition operation below will result in the value 5.14159:

2.71828 + 3.14159 

The addition operator may also be used to concatenate strings:

'hello'  + ' ' + 'world' 

If an attempt is made to concatenate a string with a number, the number will be converted into a string:

'hello number ' + 1 

This style of operation will fail if the number is used first. PowerShell expects the entire expression to be numeric if that is how it begins:

PS> 1 + ' is the number I like to use'Cannot convert value "is the number I like to use" to type "System.Int32". Error: "Input string was not in a correct format."At line:1 char:1+ 1 + ' is the number I like to use' ...