How to add space before and after contional operator in string?












2















I have the string e.g "number1<=number2&&number3>number4||number2=number4" and having operator list as -



var operators = new List<string> {"=", "!", "<", ">", ">=", "<=", "!=","||","&&"};


So expectation is need to introduce single space before and after the operator in string.



"number1 <= number2 && number3 > number4 || number2 = number4"



I have tried following option but its not working in case of eg. <, >=



    public static string AddSpaceBeforeAndAfterOperator(string expression)

    {

                var operators = new List<string> {"=", "!", "<", ">", ">=", "<=", "!=", "||", "&&"};

                foreach (var op in operators)

                {

                    var index = expression.IndexOf(op, StringComparison.Ordinal);

                    if (index >= 0)

                    {

                        if (expression.Substring(index - 1) != " ")

                        {

                            expression = expression.Insert(index-1, " ");

                        }



                        expression = expression.Insert(index + op.Length + 1, " ");

                    }

                }



                return expression;

}


Note: Operator list is coming as random.



Any help appreciated!






c# string c#-4.0







share|improve this question























  • You could construct a regex by "(" + string.Join("|", operators.Select(Regex.Escape)) + ")" and then doing a regex.Replace

    – Klaus Gütter
    Nov 15 '18 at 6:45
















2















I have the string e.g "number1<=number2&&number3>number4||number2=number4" and having operator list as -



var operators = new List<string> {"=", "!", "<", ">", ">=", "<=", "!=","||","&&"};


So expectation is need to introduce single space before and after the operator in string.



"number1 <= number2 && number3 > number4 || number2 = number4"



I have tried following option but its not working in case of eg. <, >=



    public static string AddSpaceBeforeAndAfterOperator(string expression)

    {

                var operators = new List<string> {"=", "!", "<", ">", ">=", "<=", "!=", "||", "&&"};

                foreach (var op in operators)

                {

                    var index = expression.IndexOf(op, StringComparison.Ordinal);

                    if (index >= 0)

                    {

                        if (expression.Substring(index - 1) != " ")

                        {

                            expression = expression.Insert(index-1, " ");

                        }



                        expression = expression.Insert(index + op.Length + 1, " ");

                    }

                }



                return expression;

}


Note: Operator list is coming as random.



Any help appreciated!






c# string c#-4.0







share|improve this question























  • You could construct a regex by "(" + string.Join("|", operators.Select(Regex.Escape)) + ")" and then doing a regex.Replace

    – Klaus Gütter
    Nov 15 '18 at 6:45














2












2








2








I have the string e.g "number1<=number2&&number3>number4||number2=number4" and having operator list as -



var operators = new List<string> {"=", "!", "<", ">", ">=", "<=", "!=","||","&&"};


So expectation is need to introduce single space before and after the operator in string.



"number1 <= number2 && number3 > number4 || number2 = number4"



I have tried following option but its not working in case of eg. <, >=



    public static string AddSpaceBeforeAndAfterOperator(string expression)

    {

                var operators = new List<string> {"=", "!", "<", ">", ">=", "<=", "!=", "||", "&&"};

                foreach (var op in operators)

                {

                    var index = expression.IndexOf(op, StringComparison.Ordinal);

                    if (index >= 0)

                    {

                        if (expression.Substring(index - 1) != " ")

                        {

                            expression = expression.Insert(index-1, " ");

                        }



                        expression = expression.Insert(index + op.Length + 1, " ");

                    }

                }



                return expression;

}


Note: Operator list is coming as random.



Any help appreciated!






c# string c#-4.0







share|improve this question














I have the string e.g "number1<=number2&&number3>number4||number2=number4" and having operator list as -



var operators = new List<string> {"=", "!", "<", ">", ">=", "<=", "!=","||","&&"};


So expectation is need to introduce single space before and after the operator in string.



"number1 <= number2 && number3 > number4 || number2 = number4"



I have tried following option but its not working in case of eg. <, >=



    public static string AddSpaceBeforeAndAfterOperator(string expression)

    {

                var operators = new List<string> {"=", "!", "<", ">", ">=", "<=", "!=", "||", "&&"};

                foreach (var op in operators)

                {

                    var index = expression.IndexOf(op, StringComparison.Ordinal);

                    if (index >= 0)

                    {

                        if (expression.Substring(index - 1) != " ")

                        {

                            expression = expression.Insert(index-1, " ");

                        }



                        expression = expression.Insert(index + op.Length + 1, " ");

                    }

                }



                return expression;

}


Note: Operator list is coming as random.



Any help appreciated!






c# string c#-4.0




c# string c#-4.0






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 15 '18 at 6:39









Sumit DeshpandeSumit Deshpande

1,62611326




1,62611326













  • You could construct a regex by "(" + string.Join("|", operators.Select(Regex.Escape)) + ")" and then doing a regex.Replace

    – Klaus Gütter
    Nov 15 '18 at 6:45



















  • You could construct a regex by "(" + string.Join("|", operators.Select(Regex.Escape)) + ")" and then doing a regex.Replace

    – Klaus Gütter
    Nov 15 '18 at 6:45

















You could construct a regex by "(" + string.Join("|", operators.Select(Regex.Escape)) + ")" and then doing a regex.Replace

– Klaus Gütter
Nov 15 '18 at 6:45





You could construct a regex by "(" + string.Join("|", operators.Select(Regex.Escape)) + ")" and then doing a regex.Replace

– Klaus Gütter
Nov 15 '18 at 6:45












2 Answers
2






active

oldest

votes


















3














I would recommend a regex solution.



First, you need to escape all your operators, join them together with |:



var operatorsString = string.Join("|", 

    operators.OrderByDescending(x => x.Length).Select(Regex.Escape).ToArray()

);

// OrderByDescending here because we want the longer operators to be matched first.


Next, create the regex:



var regex = $"\s*({operatorString})\s*";


Using the operators array in the question, the array looks like this:



s*(<=|>=|!=|==||||&&|=|!|<|>)s?*


Note that s* is used to check if the operator is already surrounded by spaces. If it is, those spaces will be matched and replaced.



The replacement is:



 $1


Code:



Regex.Replace(input, regex, " $1 ");


Note the leading and trailing space.



Also note that Regex is inside the System.Text.RegularExpressions namespace.



Demo






share|improve this answer


























  • Probably, a better choice s* instead of s? for "if the operator is already surrounded by spaces" (what if we have several spaces: "a___>=__b"?)

    – Dmitry Bychenko
    Nov 15 '18 at 7:55













  • @DmitryBychenko Good point. Edited.

    – Sweeper
    Nov 15 '18 at 8:21











  • @Sweeper - Thanks for the suggestion.

    – Sumit Deshpande
    Nov 16 '18 at 5:14



















1














Im not sure if this is the most effective way to do this, but is is rally simple by using replace



public static string AddSpaceBeforeAndAfterOperator(string expression)

{

    var operators = new List<string> { "=", "!", "<", ">", ">=", "<=", "!=", "||", "&&" };

    foreach (var op in operators)

    {

        expression = expression.Replace(op, " " + op + " ");

    }



    return expression;

 }





share|improve this answer



















  • 2





    Thanks for the suggestion, But this is not going to work in case of a scenario like "number1<=number2" it will end up returning "number1 < = number2" which is not correct

    – Sumit Deshpande
    Nov 15 '18 at 6:52













  • wont work for <= will result < =

    – styx
    Nov 15 '18 at 6:53











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2 Answers
2






active

oldest

votes








2 Answers
2






active

oldest

votes









active

oldest

votes






active

oldest

votes









3














I would recommend a regex solution.



First, you need to escape all your operators, join them together with |:



var operatorsString = string.Join("|", 

    operators.OrderByDescending(x => x.Length).Select(Regex.Escape).ToArray()

);

// OrderByDescending here because we want the longer operators to be matched first.


Next, create the regex:



var regex = $"\s*({operatorString})\s*";


Using the operators array in the question, the array looks like this:



s*(<=|>=|!=|==||||&&|=|!|<|>)s?*


Note that s* is used to check if the operator is already surrounded by spaces. If it is, those spaces will be matched and replaced.



The replacement is:



 $1


Code:



Regex.Replace(input, regex, " $1 ");


Note the leading and trailing space.



Also note that Regex is inside the System.Text.RegularExpressions namespace.



Demo






share|improve this answer


























  • Probably, a better choice s* instead of s? for "if the operator is already surrounded by spaces" (what if we have several spaces: "a___>=__b"?)

    – Dmitry Bychenko
    Nov 15 '18 at 7:55













  • @DmitryBychenko Good point. Edited.

    – Sweeper
    Nov 15 '18 at 8:21











  • @Sweeper - Thanks for the suggestion.

    – Sumit Deshpande
    Nov 16 '18 at 5:14
















3














I would recommend a regex solution.



First, you need to escape all your operators, join them together with |:



var operatorsString = string.Join("|", 

    operators.OrderByDescending(x => x.Length).Select(Regex.Escape).ToArray()

);

// OrderByDescending here because we want the longer operators to be matched first.


Next, create the regex:



var regex = $"\s*({operatorString})\s*";


Using the operators array in the question, the array looks like this:



s*(<=|>=|!=|==||||&&|=|!|<|>)s?*


Note that s* is used to check if the operator is already surrounded by spaces. If it is, those spaces will be matched and replaced.



The replacement is:



 $1


Code:



Regex.Replace(input, regex, " $1 ");


Note the leading and trailing space.



Also note that Regex is inside the System.Text.RegularExpressions namespace.



Demo






share|improve this answer


























  • Probably, a better choice s* instead of s? for "if the operator is already surrounded by spaces" (what if we have several spaces: "a___>=__b"?)

    – Dmitry Bychenko
    Nov 15 '18 at 7:55













  • @DmitryBychenko Good point. Edited.

    – Sweeper
    Nov 15 '18 at 8:21











  • @Sweeper - Thanks for the suggestion.

    – Sumit Deshpande
    Nov 16 '18 at 5:14














3












3








3







I would recommend a regex solution.



First, you need to escape all your operators, join them together with |:



var operatorsString = string.Join("|", 

    operators.OrderByDescending(x => x.Length).Select(Regex.Escape).ToArray()

);

// OrderByDescending here because we want the longer operators to be matched first.


Next, create the regex:



var regex = $"\s*({operatorString})\s*";


Using the operators array in the question, the array looks like this:



s*(<=|>=|!=|==||||&&|=|!|<|>)s?*


Note that s* is used to check if the operator is already surrounded by spaces. If it is, those spaces will be matched and replaced.



The replacement is:



 $1


Code:



Regex.Replace(input, regex, " $1 ");


Note the leading and trailing space.



Also note that Regex is inside the System.Text.RegularExpressions namespace.



Demo






share|improve this answer















I would recommend a regex solution.



First, you need to escape all your operators, join them together with |:



var operatorsString = string.Join("|", 

    operators.OrderByDescending(x => x.Length).Select(Regex.Escape).ToArray()

);

// OrderByDescending here because we want the longer operators to be matched first.


Next, create the regex:



var regex = $"\s*({operatorString})\s*";


Using the operators array in the question, the array looks like this:



s*(<=|>=|!=|==||||&&|=|!|<|>)s?*


Note that s* is used to check if the operator is already surrounded by spaces. If it is, those spaces will be matched and replaced.



The replacement is:



 $1


Code:



Regex.Replace(input, regex, " $1 ");


Note the leading and trailing space.



Also note that Regex is inside the System.Text.RegularExpressions namespace.



Demo







share|improve this answer














share|improve this answer



share|improve this answer








edited Nov 15 '18 at 8:20

























answered Nov 15 '18 at 6:54









SweeperSweeper

68.8k1073140




68.8k1073140













  • Probably, a better choice s* instead of s? for "if the operator is already surrounded by spaces" (what if we have several spaces: "a___>=__b"?)

    – Dmitry Bychenko
    Nov 15 '18 at 7:55













  • @DmitryBychenko Good point. Edited.

    – Sweeper
    Nov 15 '18 at 8:21











  • @Sweeper - Thanks for the suggestion.

    – Sumit Deshpande
    Nov 16 '18 at 5:14



















  • Probably, a better choice s* instead of s? for "if the operator is already surrounded by spaces" (what if we have several spaces: "a___>=__b"?)

    – Dmitry Bychenko
    Nov 15 '18 at 7:55













  • @DmitryBychenko Good point. Edited.

    – Sweeper
    Nov 15 '18 at 8:21











  • @Sweeper - Thanks for the suggestion.

    – Sumit Deshpande
    Nov 16 '18 at 5:14

















Probably, a better choice s* instead of s? for "if the operator is already surrounded by spaces" (what if we have several spaces: "a___>=__b"?)

– Dmitry Bychenko
Nov 15 '18 at 7:55







Probably, a better choice s* instead of s? for "if the operator is already surrounded by spaces" (what if we have several spaces: "a___>=__b"?)

– Dmitry Bychenko
Nov 15 '18 at 7:55















@DmitryBychenko Good point. Edited.

– Sweeper
Nov 15 '18 at 8:21





@DmitryBychenko Good point. Edited.

– Sweeper
Nov 15 '18 at 8:21













@Sweeper - Thanks for the suggestion.

– Sumit Deshpande
Nov 16 '18 at 5:14





@Sweeper - Thanks for the suggestion.

– Sumit Deshpande
Nov 16 '18 at 5:14













1














Im not sure if this is the most effective way to do this, but is is rally simple by using replace



public static string AddSpaceBeforeAndAfterOperator(string expression)

{

    var operators = new List<string> { "=", "!", "<", ">", ">=", "<=", "!=", "||", "&&" };

    foreach (var op in operators)

    {

        expression = expression.Replace(op, " " + op + " ");

    }



    return expression;

 }





share|improve this answer



















  • 2





    Thanks for the suggestion, But this is not going to work in case of a scenario like "number1<=number2" it will end up returning "number1 < = number2" which is not correct

    – Sumit Deshpande
    Nov 15 '18 at 6:52













  • wont work for <= will result < =

    – styx
    Nov 15 '18 at 6:53
















1














Im not sure if this is the most effective way to do this, but is is rally simple by using replace



public static string AddSpaceBeforeAndAfterOperator(string expression)

{

    var operators = new List<string> { "=", "!", "<", ">", ">=", "<=", "!=", "||", "&&" };

    foreach (var op in operators)

    {

        expression = expression.Replace(op, " " + op + " ");

    }



    return expression;

 }





share|improve this answer



















  • 2





    Thanks for the suggestion, But this is not going to work in case of a scenario like "number1<=number2" it will end up returning "number1 < = number2" which is not correct

    – Sumit Deshpande
    Nov 15 '18 at 6:52













  • wont work for <= will result < =

    – styx
    Nov 15 '18 at 6:53














1












1








1







Im not sure if this is the most effective way to do this, but is is rally simple by using replace



public static string AddSpaceBeforeAndAfterOperator(string expression)

{

    var operators = new List<string> { "=", "!", "<", ">", ">=", "<=", "!=", "||", "&&" };

    foreach (var op in operators)

    {

        expression = expression.Replace(op, " " + op + " ");

    }



    return expression;

 }





share|improve this answer













Im not sure if this is the most effective way to do this, but is is rally simple by using replace



public static string AddSpaceBeforeAndAfterOperator(string expression)

{

    var operators = new List<string> { "=", "!", "<", ">", ">=", "<=", "!=", "||", "&&" };

    foreach (var op in operators)

    {

        expression = expression.Replace(op, " " + op + " ");

    }



    return expression;

 }






share|improve this answer












share|improve this answer



share|improve this answer










answered Nov 15 '18 at 6:47









Daniel W.Daniel W.

226111




226111








  • 2





    Thanks for the suggestion, But this is not going to work in case of a scenario like "number1<=number2" it will end up returning "number1 < = number2" which is not correct

    – Sumit Deshpande
    Nov 15 '18 at 6:52













  • wont work for <= will result < =

    – styx
    Nov 15 '18 at 6:53














  • 2





    Thanks for the suggestion, But this is not going to work in case of a scenario like "number1<=number2" it will end up returning "number1 < = number2" which is not correct

    – Sumit Deshpande
    Nov 15 '18 at 6:52













  • wont work for <= will result < =

    – styx
    Nov 15 '18 at 6:53








2




2





Thanks for the suggestion, But this is not going to work in case of a scenario like "number1<=number2" it will end up returning "number1 < = number2" which is not correct

– Sumit Deshpande
Nov 15 '18 at 6:52







Thanks for the suggestion, But this is not going to work in case of a scenario like "number1<=number2" it will end up returning "number1 < = number2" which is not correct

– Sumit Deshpande
Nov 15 '18 at 6:52















wont work for <= will result < =

– styx
Nov 15 '18 at 6:53





wont work for <= will result < =

– styx
Nov 15 '18 at 6:53


















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