Question

How to check if a string contain plus or minus before the digits in JavaScript

Answer 1

function is_plus_minus_and_numeric(s) {
      var only_digits = /^[-+]?[0-9]+$/;
      if (s.match(only_digits)) {
          return true;
      }
      else {
          return false;
      }
   } 

var s = '+37';
document.write(is_plus_minus_and_numeric(s) + "<br />");

s = '98375';
document.write(is_plus_minus_and_numeric(s) + "<br />");

s = '-98';
document.write(is_plus_minus_and_numeric(s) + "<br />");

s = '8+9';
document.write(is_plus_minus_and_numeric(s) + "<br />");

s = '+-89';
document.write(is_plus_minus_and_numeric(s) + "<br />");
 
     
/*
run:
 
true
true
true
false
false
          
*/

 

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