C++ In a Nutshell

Name

new operator — Allocates a dynamic object or array of objects

Synopsis

               new-expr ::= [::] new [placement] new-type-id [new-initializer] | 
    [::] new [placement] ( type-id ) [new-initializer]
placement ::= ( expr-list )
new-type-id ::= type-specifier-seq [new-declarator]
new-declarator ::= ptr-operator [new-declarator] | direct-new-declarator
               direct-new-declarator ::= "[" expression "]" | 
    direct-new-declarator "[" constant-expr "]"
new-initializer ::= ( [expr-list] )
ptr-operator ::= * [cv-qualifier-seq] | & | [::] nested-name :: * [cv-qualifier-seq]

The new expression allocates memory and constructs an object. It has many forms, the simplest being a simple type name (e.g., new int). The new-type-id can be a sequence of type specifiers and qualifiers, with pointer operators, a reference operator, and an array size (e.g., new int*[n][42], which allocates a two-dimensional array of pointers to int with n rows and 42 columns). The first dimension can be an integral expression; the second and subsequent dimensions must be constant expressions. If the type contains parentheses, such as function pointers, you should enclose it in parentheses to avoid ambiguity.

The new expression calls an allocator function to allocate the necessary memory, then initializes the memory. The new-initializer is an optional list of expressions in parentheses. If no new-initializer is present, the new object is initialized to its default value: POD objects are uninitialized, and other objects are initialized ...