Measuring length of string in pixel in javascript

Question

如果我知道font-size和font-family，如何在javascript中找到字符串的长度（以像素为单位）？

Answer 1

The simplest solution is to create an in memory canvas (ie one that isn't added to the DOM) and then use the measureText function :

var canvas = document.createElement('canvas');
var ctx = canvas.getContext("2d");
ctx.font = "11px Arial";        
var width = ctx.measureText(str).width;

Answer 2

you can put your string into paragraph and use the jquery width function to get the width in pixel width

    function showWidth(ele, w) {
$("div").text("The width for the " + ele +
" is " + w + "px.");
}
$("#getp").click(function () {
showWidth("paragraph", $("p").width());
});

check jsfiddle