JavaScript let if else statement args












0















I'm trying to define a let in JavaScript so that if there's no arg[2], then it will just use arg[1], but if there is arg[1] and arg[2] it will use them both.



ie. command: !hello world
then: let cmd = arg[1]


but also



command: !hello world one
then: let cmd = arg[1] + " " + arg[2]


I have this, however it only works if arg[2] exists, and doesn't if only arg[1] is supplied:



let cmd = args[1] + " " + args[2];


Is there anyway you can specify an arg to pass through spaces? So !hello world one, would be arg[1] arg[2] (arg[2] being: world one)










share|improve this question




















  • 1





    You seem to be asking two very different questions: (1) how to deal with an optional second argument and (2) how to pass an argument that contains spaces. It's not clear if you're asking the second question as a way of dealing with the first or if it's a separate issue. The first issue can be handled with a ternary expression: let cmd = arg[2] === undefined ? arg[1] + " " + arg[2] : arg[1];.

    – Ted Hopp
    Nov 14 '18 at 1:58








  • 1





    let cmd = args.join(" "); would suffice if you didn't mind them possibly supplying more than two arguments.

    – Tyler Roper
    Nov 14 '18 at 2:02











  • Thank you. @TedHopp, how would I go about the second, where args[3] would contain everything from args[3] and onward?

    – ah1
    Nov 14 '18 at 18:58






  • 1





    You can use what @Tyler suggested and collect all remaining arguments with something like args.slice(3).join(" ") (which would create a single string containing all elements of arg from index 3 onward, separated by a space).

    – Ted Hopp
    Nov 14 '18 at 19:36
















0















I'm trying to define a let in JavaScript so that if there's no arg[2], then it will just use arg[1], but if there is arg[1] and arg[2] it will use them both.



ie. command: !hello world
then: let cmd = arg[1]


but also



command: !hello world one
then: let cmd = arg[1] + " " + arg[2]


I have this, however it only works if arg[2] exists, and doesn't if only arg[1] is supplied:



let cmd = args[1] + " " + args[2];


Is there anyway you can specify an arg to pass through spaces? So !hello world one, would be arg[1] arg[2] (arg[2] being: world one)










share|improve this question




















  • 1





    You seem to be asking two very different questions: (1) how to deal with an optional second argument and (2) how to pass an argument that contains spaces. It's not clear if you're asking the second question as a way of dealing with the first or if it's a separate issue. The first issue can be handled with a ternary expression: let cmd = arg[2] === undefined ? arg[1] + " " + arg[2] : arg[1];.

    – Ted Hopp
    Nov 14 '18 at 1:58








  • 1





    let cmd = args.join(" "); would suffice if you didn't mind them possibly supplying more than two arguments.

    – Tyler Roper
    Nov 14 '18 at 2:02











  • Thank you. @TedHopp, how would I go about the second, where args[3] would contain everything from args[3] and onward?

    – ah1
    Nov 14 '18 at 18:58






  • 1





    You can use what @Tyler suggested and collect all remaining arguments with something like args.slice(3).join(" ") (which would create a single string containing all elements of arg from index 3 onward, separated by a space).

    – Ted Hopp
    Nov 14 '18 at 19:36














0












0








0








I'm trying to define a let in JavaScript so that if there's no arg[2], then it will just use arg[1], but if there is arg[1] and arg[2] it will use them both.



ie. command: !hello world
then: let cmd = arg[1]


but also



command: !hello world one
then: let cmd = arg[1] + " " + arg[2]


I have this, however it only works if arg[2] exists, and doesn't if only arg[1] is supplied:



let cmd = args[1] + " " + args[2];


Is there anyway you can specify an arg to pass through spaces? So !hello world one, would be arg[1] arg[2] (arg[2] being: world one)










share|improve this question
















I'm trying to define a let in JavaScript so that if there's no arg[2], then it will just use arg[1], but if there is arg[1] and arg[2] it will use them both.



ie. command: !hello world
then: let cmd = arg[1]


but also



command: !hello world one
then: let cmd = arg[1] + " " + arg[2]


I have this, however it only works if arg[2] exists, and doesn't if only arg[1] is supplied:



let cmd = args[1] + " " + args[2];


Is there anyway you can specify an arg to pass through spaces? So !hello world one, would be arg[1] arg[2] (arg[2] being: world one)







javascript let






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 14 '18 at 1:58









Pedro Lobito

48.4k14133164




48.4k14133164










asked Nov 14 '18 at 1:51









ah1ah1

168




168








  • 1





    You seem to be asking two very different questions: (1) how to deal with an optional second argument and (2) how to pass an argument that contains spaces. It's not clear if you're asking the second question as a way of dealing with the first or if it's a separate issue. The first issue can be handled with a ternary expression: let cmd = arg[2] === undefined ? arg[1] + " " + arg[2] : arg[1];.

    – Ted Hopp
    Nov 14 '18 at 1:58








  • 1





    let cmd = args.join(" "); would suffice if you didn't mind them possibly supplying more than two arguments.

    – Tyler Roper
    Nov 14 '18 at 2:02











  • Thank you. @TedHopp, how would I go about the second, where args[3] would contain everything from args[3] and onward?

    – ah1
    Nov 14 '18 at 18:58






  • 1





    You can use what @Tyler suggested and collect all remaining arguments with something like args.slice(3).join(" ") (which would create a single string containing all elements of arg from index 3 onward, separated by a space).

    – Ted Hopp
    Nov 14 '18 at 19:36














  • 1





    You seem to be asking two very different questions: (1) how to deal with an optional second argument and (2) how to pass an argument that contains spaces. It's not clear if you're asking the second question as a way of dealing with the first or if it's a separate issue. The first issue can be handled with a ternary expression: let cmd = arg[2] === undefined ? arg[1] + " " + arg[2] : arg[1];.

    – Ted Hopp
    Nov 14 '18 at 1:58








  • 1





    let cmd = args.join(" "); would suffice if you didn't mind them possibly supplying more than two arguments.

    – Tyler Roper
    Nov 14 '18 at 2:02











  • Thank you. @TedHopp, how would I go about the second, where args[3] would contain everything from args[3] and onward?

    – ah1
    Nov 14 '18 at 18:58






  • 1





    You can use what @Tyler suggested and collect all remaining arguments with something like args.slice(3).join(" ") (which would create a single string containing all elements of arg from index 3 onward, separated by a space).

    – Ted Hopp
    Nov 14 '18 at 19:36








1




1





You seem to be asking two very different questions: (1) how to deal with an optional second argument and (2) how to pass an argument that contains spaces. It's not clear if you're asking the second question as a way of dealing with the first or if it's a separate issue. The first issue can be handled with a ternary expression: let cmd = arg[2] === undefined ? arg[1] + " " + arg[2] : arg[1];.

– Ted Hopp
Nov 14 '18 at 1:58







You seem to be asking two very different questions: (1) how to deal with an optional second argument and (2) how to pass an argument that contains spaces. It's not clear if you're asking the second question as a way of dealing with the first or if it's a separate issue. The first issue can be handled with a ternary expression: let cmd = arg[2] === undefined ? arg[1] + " " + arg[2] : arg[1];.

– Ted Hopp
Nov 14 '18 at 1:58






1




1





let cmd = args.join(" "); would suffice if you didn't mind them possibly supplying more than two arguments.

– Tyler Roper
Nov 14 '18 at 2:02





let cmd = args.join(" "); would suffice if you didn't mind them possibly supplying more than two arguments.

– Tyler Roper
Nov 14 '18 at 2:02













Thank you. @TedHopp, how would I go about the second, where args[3] would contain everything from args[3] and onward?

– ah1
Nov 14 '18 at 18:58





Thank you. @TedHopp, how would I go about the second, where args[3] would contain everything from args[3] and onward?

– ah1
Nov 14 '18 at 18:58




1




1





You can use what @Tyler suggested and collect all remaining arguments with something like args.slice(3).join(" ") (which would create a single string containing all elements of arg from index 3 onward, separated by a space).

– Ted Hopp
Nov 14 '18 at 19:36





You can use what @Tyler suggested and collect all remaining arguments with something like args.slice(3).join(" ") (which would create a single string containing all elements of arg from index 3 onward, separated by a space).

– Ted Hopp
Nov 14 '18 at 19:36












3 Answers
3






active

oldest

votes


















0














I usually do something like:



const myFunction = (argA, argB) => {
if (argB === undefined) argB = "";
console.log(argA + " " + argB);
return "" + argA + " " + argB
}





share|improve this answer































    0














    You mean like:



    let test = arg[1] && arg[2] ? arg[1]+' '+arg[1] : arg[1];





    share|improve this answer































      0














      If you are using ES6 you can use the rest operator like so:



      const myFunction = (...args) => {
      console.log(args[0])
      }


      if you don't use the fat arrow syntax you can refer to the arguments key word:



          function func1(a, b, c) {
      if(arguments && arguments.length == 2){
      console.log('do a thing')
      }else{
      console.log('do a different thing')
      }
      };





      share|improve this answer

























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        3 Answers
        3






        active

        oldest

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        3 Answers
        3






        active

        oldest

        votes









        active

        oldest

        votes






        active

        oldest

        votes









        0














        I usually do something like:



        const myFunction = (argA, argB) => {
        if (argB === undefined) argB = "";
        console.log(argA + " " + argB);
        return "" + argA + " " + argB
        }





        share|improve this answer




























          0














          I usually do something like:



          const myFunction = (argA, argB) => {
          if (argB === undefined) argB = "";
          console.log(argA + " " + argB);
          return "" + argA + " " + argB
          }





          share|improve this answer


























            0












            0








            0







            I usually do something like:



            const myFunction = (argA, argB) => {
            if (argB === undefined) argB = "";
            console.log(argA + " " + argB);
            return "" + argA + " " + argB
            }





            share|improve this answer













            I usually do something like:



            const myFunction = (argA, argB) => {
            if (argB === undefined) argB = "";
            console.log(argA + " " + argB);
            return "" + argA + " " + argB
            }






            share|improve this answer












            share|improve this answer



            share|improve this answer










            answered Nov 14 '18 at 1:55









            FallenreaperFallenreaper

            3,95883483




            3,95883483

























                0














                You mean like:



                let test = arg[1] && arg[2] ? arg[1]+' '+arg[1] : arg[1];





                share|improve this answer




























                  0














                  You mean like:



                  let test = arg[1] && arg[2] ? arg[1]+' '+arg[1] : arg[1];





                  share|improve this answer


























                    0












                    0








                    0







                    You mean like:



                    let test = arg[1] && arg[2] ? arg[1]+' '+arg[1] : arg[1];





                    share|improve this answer













                    You mean like:



                    let test = arg[1] && arg[2] ? arg[1]+' '+arg[1] : arg[1];






                    share|improve this answer












                    share|improve this answer



                    share|improve this answer










                    answered Nov 14 '18 at 2:01









                    Yoannes GeisslerYoannes Geissler

                    81118




                    81118























                        0














                        If you are using ES6 you can use the rest operator like so:



                        const myFunction = (...args) => {
                        console.log(args[0])
                        }


                        if you don't use the fat arrow syntax you can refer to the arguments key word:



                            function func1(a, b, c) {
                        if(arguments && arguments.length == 2){
                        console.log('do a thing')
                        }else{
                        console.log('do a different thing')
                        }
                        };





                        share|improve this answer






























                          0














                          If you are using ES6 you can use the rest operator like so:



                          const myFunction = (...args) => {
                          console.log(args[0])
                          }


                          if you don't use the fat arrow syntax you can refer to the arguments key word:



                              function func1(a, b, c) {
                          if(arguments && arguments.length == 2){
                          console.log('do a thing')
                          }else{
                          console.log('do a different thing')
                          }
                          };





                          share|improve this answer




























                            0












                            0








                            0







                            If you are using ES6 you can use the rest operator like so:



                            const myFunction = (...args) => {
                            console.log(args[0])
                            }


                            if you don't use the fat arrow syntax you can refer to the arguments key word:



                                function func1(a, b, c) {
                            if(arguments && arguments.length == 2){
                            console.log('do a thing')
                            }else{
                            console.log('do a different thing')
                            }
                            };





                            share|improve this answer















                            If you are using ES6 you can use the rest operator like so:



                            const myFunction = (...args) => {
                            console.log(args[0])
                            }


                            if you don't use the fat arrow syntax you can refer to the arguments key word:



                                function func1(a, b, c) {
                            if(arguments && arguments.length == 2){
                            console.log('do a thing')
                            }else{
                            console.log('do a different thing')
                            }
                            };






                            share|improve this answer














                            share|improve this answer



                            share|improve this answer








                            edited Nov 14 '18 at 2:11

























                            answered Nov 14 '18 at 2:06









                            ruby_newbieruby_newbie

                            2,30521120




                            2,30521120






























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