ldc_w : push single-word constant onto stack (wide index) : index : visitLdcInsn()

Description

ldc_w pushes a one-word constant onto the operand stack. ldc_w takes a single parameter, <value>, which is the value to push. The following Java types can be pushed using ldc_w:

int float String

Pushing a String causes a reference to a java.lang.String object to be constructed and pushed onto the stack. Pusing an int or a float causes a primitive value to be pushed onto the stack.

ldc_w is identical to ldc except that, in bytecode, ldc_w uses a 16-bit index rather than an 8-bit index.

Exceptions

OutOfMemoryError - not enough memory to allocate a reference to a String

Notes

1. Where possible, its more efficient to use one of bipush, sipush, or one of the const instructions instead of ldc_w.

2. If the same string constant (i.e. a string with the same sequence of characters) appears in several different class files, only one String instance is built for that constant. The String.intern() method can be used to retrieve the instance used for a given sequence of characters.

3. The Jasmin assembler automatically determines whether to use ldc or ldc_w, so in Jasmin assembly files these two instructions are synonymous.

See also

bipush sipush ldc ldc2_w aconst_null iconst_m1 iconst_n lconst_l fconst_f dconst_d

Stack

Before	After
...	<value>
	...

Bytecode

Type	Description
u1	ldc_w opcode = 0x13 (19)
u2	index