The tag <stack.peek> returns the last object stored in the stack without removing it from it. The stack can be indicated via the
attribute name or passing it as argument.
1 stack.peek
<stack.peek name='name'>
<stack /> ?
</stack.peek>
| Attributes | |||||
|---|---|---|---|---|---|
| Name | Type | Required | Default | Description | |
| Aname | string | Stack name. | |||
| Arguments | |||||
|---|---|---|---|---|---|
| Name | Type | Required | Unique | Nullable | Description |
| Estack | Stack | ||||
| Returns | |
|---|---|
| Type | Description |
| Object | The last object which has been placed in the stack. |
Example
Initialize the execution stack with two values and obtain them through the tag stack.peek.
Copy
<xsql-script name='peek_test'>
<body>
<stack name='stack1'><number>10</number><string>hello</string></stack>
<!-- The stack is not altered -->
<set name='a'><stack.peek name='stack1' /></set>
<println><a/></println>
<!-- hello -->
<!-- Extraction of the object which is in the top of the stack, it is the same than before because the peek does not remove the stack. -->
<set name='b'><stack.peek><stack1/></stack.peek></set>
<println><b/></println>
<!-- hello -->
</body>
</xsql-script>