Java Virtual Machine (Java Series)

iconst_<n>

iconst_0 or iconst_1 or iconst_2 or iconst_3 or iconst_4 or iconst_5 Stack

iconst_<n> represents the series of opcodes iconst_0, iconst_1, iconst_2, iconst_3, iconst_4 and iconst_5. These are used to push the constant ints 0 through 5 onto the stack. For example, to push the int zero onto the stack, use:

iconst_0 ; push 0 onto the stack. Note that you could also use:

bipush 0 ; push 0 onto the stack or

sipush 0 ; push 0 onto the stack or

ldc 0 ; push 0 onto the stack although these instructions are typically less efficient than the equivalent iconst_<n> and also take up more bytes in the class file.

Example

iconst_0 ; push 0 onto the stack iconst_1 ; push 1 onto the stack iconst_2 ; push 2 onto the stack iconst_3 ; push 3 onto the stack iconst_4 ; push 4 onto the stack iconst_5 ; push 5 onto the stack Bytecode

bipush, sipush, ldc, ldc_w, ldc2_w, aconst_null, iconst_m1, lconst_<l>, fconst_<f>, dconst_<d>

Java Virtual Machine, by Jon Meyer and Troy Downing, O'Reilly Associates