The default value of variables that do not have any value is undefined. A variable name cannot be a reserved keyword in JavaScript, e.g. var, function, return cannot be variable names. Variables declared inside a { } block can be accessed from outside the block. The const the keyword was introduced in ES6 (2015). Variables defined const cannot be Redeclared.
Table of contents
Basic JavaScript — JavaScript for Beginners — Part 1JavaScript Variables:VarVariable ScopeGlobal VariablesLocal VariablesVariables Declare without var keyword:Variable Names in JavaScriptLetLet cannot be RedeclaredLet is block scopedlet can be re-initialized but not re-declared.ConstConst variables Cannot be ReassignedWhen to use JavaScript const?JavaScript String:String Concatenation:String object:JavaScript String Methods & PropertiesString Properties:Extracting String Parts in JavaScript:JavaScript String slice()JavaScript substring():JavaScript substr():Replace method in JavaScript:JavaScript String toUpperCase():JavaScript String toLowerCase():JavaScript String trim():Challenge 1#JavaScript Numbers:Challenge 2#Challenge #32 Comments
Sort: