Why Does ' ' Concatenate Strings But '-' Subtracts Numbers in JavaScript?

Divergent Behavior of ' ' and '-' Operators with Strings and Numbers in JavaScript

JavaScript exhibits a puzzling behavior when performing mathematical operations between strings and numbers. Specifically, the behavior of the ' ' and '-' operators varies depending on the operand types involved.

Let's delve into two examples to illustrate this observation:

1. String Concatenation ( ):

   console.log("1" + 1);

   Output: "11"

2. Number Subtraction (-):

   console.log("1" - 1);

   Output: 0

Reasoning:

1. String Concatenation: The ' ' operator performs string concatenation when one of the operands is a string. In the first example, "1" is a string, so JavaScript converts the numeric 1 to a string and concatenates them, resulting in "11".
2. Number Subtraction: On the other hand, the '-' operator cannot perform subtraction on strings. Instead, JavaScript attempts to convert the string operand ("1" in the second example) to a number. This conversion succeeds because "1" can be validly interpreted as a numeric value. However, the resulting subtraction of 1 from 1 yields 0.

This behavior stems from the fact that JavaScript adheres to the "loose typing" paradigm, where type coercion is automatically performed to make operations compatible. However, in the case of the '-' operator and strings, type coercion cannot be applied, leading to the observed behavior.

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