Why Does Adding Strings in JavaScript Result in Concatenation Instead of Numerical Addition?

Resolving Unexpected String Concatenation in Numerical Addition

Problem: When attempting to add two numbers represented by strings, the result is incorrect because they are concatenated instead of being summed. For instance, 1 2 returns "12" instead of 3.

Code Snippet:

var y = document.getElementById("txt1").value;
var z = document.getElementById("txt2").value;
var x = y + z;

Explanation: The values of y and z are retrieved as strings from the HTML input elements. When these strings are added using the ' ' operator, JavaScript treats them as text and concatenates them instead of performing a mathematical addition.

Solution: To resolve this issue, the strings must be converted to numbers before performing addition. This can be achieved by prepending the ' ' operator to each string.

var x = +y + +z;

In this modified code, the ' ' operator is used to coerce the strings into numbers before they are added together. This will ensure that 1 2 returns the correct sum of 3, rather than the concatenated string "12".

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