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How to validate multiple line values using JavaScript and Regular Expression.
Problem: I want to validate if my textarea contains only number. But my textarea accepts multiple Number values separated by break line.
1234
6743
2934
2134

Solutions:

1. Merge the value into single line of code by replacing the end of line character with empty string
2. Check if the value is number using regular expression

function isNumber(value){
   var pattern = new RegExp("^[0-9]+$");
   value = value.replace(/\n/g,"");
   return pattern.test(value);
}