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JavaScript Variables Explained: When to Use var, let, and const

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A variable in JavaScript is a named container used to store values that can be referenced or updated throughout a program. JavaScript provides three keywords for declaring variables: var, the older method, and let and const, the modern alternatives. The let keyword is used when a value may change over time, such as a shopping cart total, while const is used for values that remain fixed, such as a roll number. When using const, a value must be assigned at the point of declaration and cannot be left empty. Developers are also advised to follow naming rules such as starting with a letter, avoiding reserved words, and using descriptive camelCase names for better code readability.

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JavaScript Variables Explained: When to Use var, let, and const · ShortSingh