client.elements('xpath', ".//a[@class='abcd')]", function (allButtons){
        console.log('Element value is '+element)
        allButtons.value.forEach(function (element) {
            this.elementIdClick(element, function(res){});
    }
}

TypeError: Object #<Object> has no method 'elementIdClick'

client.elements('xpath', ".//a[@class='abcd')]", function (allButtons){

allButtons.value.forEach(function (element) {
    console.log('Element value is '+element)
    this.elementIdClick(this.elementIdAttribute(allButtons.value[element].ELEMENT, 'id'), function(res){});

Element value is [object Object]
    TypeError: Cannot read property 'ELEMENT' of undefined

function iter(elems) {
    elems.value.forEach(function(element) {
        client.elementIdClick(element.ELEMENT)
    })
};
client.elements('css selector', 'button.my-button.to-iterate', iter);

client.elements('xpath', ".//a[@class='abcd')]", function (allButtons){

    allButtons.value.forEach(function (index) {
    console.log('Element value is '+index.ELEMENT)
    client.elementIdClick(index.ELEMENT);}})

// Executing a function in the application context.
client.execute(function () {

  // Get elements by CSS selector.
  var elements = document.querySelectorAll('.elements');

  // Iterate over them.
  [].forEach.call(elements, function (element) {

    // Manipulate each element.
    element.click();
  });
});