Require template literals instead of string concatenation JS-0246
Anti-pattern
Minor
a month ago
—
a year old
Unexpected string concatenation
1var clear="img/clear.gif" //path to clear.gif
2
3pngfix=function(){var els=document.getElementsByTagName('*');var ip=/\.png/i;var i=els.length;while(i-- >0){var el=els[i];var es=el.style;if(el.src&&el.src.match(ip)&&!es.filter){es.height=el.height;es.width=el.width;es.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+el.src+"',sizingMethod='crop')";el.src=clear;}else{var elb=el.currentStyle.backgroundImage;if(elb.match(ip)){var path=elb.split('"');var rep=(el.currentStyle.backgroundRepeat=='no-repeat')?'crop':'scale';es.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+path[1]+"',sizingMethod='"+rep+"')";es.height=el.clientHeight+'px';es.backgroundImage='none';var elkids=el.getElementsByTagName('*');if (elkids){var j=elkids.length;if(el.currentStyle.position!="absolute")es.position='static';while (j-- >0)if(!elkids[j].style.position)elkids[j].style.position="relative";}}}}}4window.attachEvent('onload',pngfix);
Unexpected string concatenation
1var clear="img/clear.gif" //path to clear.gif
2
3pngfix=function(){var els=document.getElementsByTagName('*');var ip=/\.png/i;var i=els.length;while(i-- >0){var el=els[i];var es=el.style;if(el.src&&el.src.match(ip)&&!es.filter){es.height=el.height;es.width=el.width;es.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+el.src+"',sizingMethod='crop')";el.src=clear;}else{var elb=el.currentStyle.backgroundImage;if(elb.match(ip)){var path=elb.split('"');var rep=(el.currentStyle.backgroundRepeat=='no-repeat')?'crop':'scale';es.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+path[1]+"',sizingMethod='"+rep+"')";es.height=el.clientHeight+'px';es.backgroundImage='none';var elkids=el.getElementsByTagName('*');if (elkids){var j=elkids.length;if(el.currentStyle.position!="absolute")es.position='static';while (j-- >0)if(!elkids[j].style.position)elkids[j].style.position="relative";}}}}}4window.attachEvent('onload',pngfix);
Unexpected string concatenation
1var clear="img/clear.gif" //path to clear.gif
2
3pngfix=function(){var els=document.getElementsByTagName('*');var ip=/\.png/i;var i=els.length;while(i-- >0){var el=els[i];var es=el.style;if(el.src&&el.src.match(ip)&&!es.filter){es.height=el.height;es.width=el.width;es.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+el.src+"',sizingMethod='crop')";el.src=clear;}else{var elb=el.currentStyle.backgroundImage;if(elb.match(ip)){var path=elb.split('"');var rep=(el.currentStyle.backgroundRepeat=='no-repeat')?'crop':'scale';es.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+path[1]+"',sizingMethod='"+rep+"')";es.height=el.clientHeight+'px';es.backgroundImage='none';var elkids=el.getElementsByTagName('*');if (elkids){var j=elkids.length;if(el.currentStyle.position!="absolute")es.position='static';while (j-- >0)if(!elkids[j].style.position)elkids[j].style.position="relative";}}}}}4window.attachEvent('onload',pngfix);
Unexpected string concatenation
197 } else {
198
199 if (document.getElementById('uniTipP')) {
200 tippointin.style.left = (TipWidth >= WinWidth ) ? "-" + elewidth + "px" : "0px";201 tippointin.style.top = "0px";
202 } else tippoint.style.backgroundPosition = (TipWidth >= WinWidth ) ? "right top" : "left top";
203 Unexpected string concatenation
192 } else tippoint.style.backgroundPosition = (TipWidth >= WinWidth ) ? "right bottom" : "left bottom";
193
194 if (document.getElementById('uniTipC')) tipcapin.style.top = "-" + CapHeight + "px";
195 else tipcap.style.backgroundPosition = "0 -" + CapHeight + "px";196
197 } else {
198
Description
In ES2015 (ES6), we can use template literals instead of string concatenation.
var str = `Hello, ${name}!`;
Bad Practice
var str = "Hello, " + name + "!";
var str = "Time: " + (12 * 60 * 60 * 1000);
Recommended
var str = "Hello World!";
var str = `Hello, ${name}!`;
var str = `Time: ${12 * 60 * 60 * 1000}`;
var str = "Hello, " + "World!";