如何从resize函数中访问变量值

Question

我有一个else..if语句，根据window.width为变量赋值，我想要做的是在window.resize中使用这个值，但此刻得到'undefined' currentSize的值//Code ran onload if(windowWidth >= 924) { incrementValue = 3; currentSize = 'desktop'; } else if(windowWidth > 615 && windowWidth < 924) { incrementValue = 2; currentSize = 'tablet'; } else { incrementValue = 1; currentSize = 'mobile'; } $(window).resize(function() { windowWidth = $(window).width(); if(windowWidth >= 924) { incrementValue = 3; var newSize = 'desktop'; } else if(windowWidth > 615 && windowWidth < 924) { incrementValue = 2; var newSize = 'tablet'; } else { incrementValue = 1; var newSize = 'mobile'; } console.log(currentSize); //'undefined' if (currentSize !== newSize) { var currentSize = newSize; incrementTotal = 0; slideIndex = 0; //Reset slider to start $carouselSlides.css( 'left', 0 );     } }); 。我应该怎么做以获得价值？

JS

{{1}}

Answer 1

请勿使用currentSize这样重新定义var

if (currentSize !== newSize) {
    var currentSize = newSize;

删除var

if (currentSize !== newSize) {
    currentSize = newSize;

以下示例允许您根据var的存在重现或消除错误：

• http://jsfiddle.net/94zVg/2/
• http://jsfiddle.net/94zVg/3/

Answer 2

<script>
//global scope
var currentSize = 'desktop', incrementTotal = 0, incrementValue = 0, slideIndex = 0, $carouselSlides = $('#carouselSlides');

function windowResize(windowWidth) {
    var data = [];
    if (windowWidth >= 924) {
        data = ['desktop', 3];
    } else if (windowWidth > 615 && windowWidth < 924) {
        data = ['tablet', 2];
    } else {
        data = ['mobile', 1];
    }
    return data.length ? data : false;
}


$(window).resize(function() {
    var windowWidth = $(this).width();
    var data = windowResize(windowWidth);
    // data[0] = desktop, tablet OR mobile
    // data[1] = 1, 2 OR 3
    incrementValue = data[1];

    if (currentSize !== data[0]) {
        currentSize = data[0];

        incrementTotal = 0;
        slideIndex = 0;

        //Reset slider to start
        $carouselSlides.css('left', 0);
    }    

    // set the style for the current screen size   
});
</script>

Answer 3

你的newSize超出了范围：

$(window).resize(function() {
   windowWidth = $(window).width();
var newSize =0;
   if(windowWidth >= 924){
      incrementValue = 3;
        newSize = 'desktop';
    } else if(windowWidth > 615 && windowWidth < 924) {
      incrementValue = 2;
      newSize = 'tablet';
    } else {
      incrementValue = 1;
      newSize = 'mobile';
    }

    if (currentSize !== newSize) {
      var currentSize = newSize;

      incrementTotal = 0;
      slideIndex = 0;

      //Reset slider to start
      $carouselSlides.css( 'left', 0 );
    }
  });