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

Description

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

int float String

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

Exceptions

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

Example

ldc "Hello World"     ; push string "Hello World" onto stack
ldc 10                ; push the integer 10
ldc 1.54              ; push the single-precision float 1.54

Notes

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

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.

See also

bipush sipush ldc_w ldc2_w aconst_null iconst_m1 iconst_n lconst_l fconst_f dconst_d

Stack

Before	After
...	<value>
	...

Bytecode

Type	Description
u1	ldc opcode = 0x12 (18)
u1	index