JavaScript中的賦值運算能夠分爲簡單賦值運算和複合賦值運算。簡單賦值運算是將賦值運算符(=)右邊表達式的值保存到左邊的變量中;而複合賦值運算混合了其餘操做(例如算術運算操做)和賦值操做。
1. = : 將右邊表達式的值賦給左邊的變量javascript
<!DOCTYPE html> <html> <head> <title></title> </head> <body> <script type="text/javascript"> var a = 10;//這裏就是值賦 </script> </body> </html>
2. += : 將運算符左邊的變量加上右邊表達式的值賦給左邊的變量html
<!DOCTYPE html> <html> <head> <title></title> </head> <body> <script type="text/javascript"> var a = 1; console.log( a+=2 ); //a=a+2 </script> </body> </html>
3. -= : 將運算符左邊的變量減去右邊表達式的值賦給左邊的變量java
<!DOCTYPE html> <html> <head> <title></title> </head> <body> <script type="text/javascript"> var a = 1; console.log( a-=2 ); //a=a-2 </script> </body> </html>
4. *= : 將運算符左邊的變量乘以右邊表達式的值賦給左邊的變量code
<!DOCTYPE html> <html> <head> <title></title> </head> <body> <script type="text/javascript"> var a = 1; console.log( a*=2 ); //a=a*2 </script> </body> </html>
5. /= : 將運算符左邊的變量除以右邊表達式的值賦給左邊的變量htm
<!DOCTYPE html> <html> <head> <title></title> </head> <body> <script type="text/javascript"> var a = 1; console.log( a/=2 ); //a=a/2 </script> </body> </html>
6. %= : 將運算符左邊的變量用右邊表達式的值求模,並將結果賦給左邊的變量ip
<!DOCTYPE html> <html> <head> <title></title> </head> <body> <script type="text/javascript"> var a = 1; console.log( a%=2 ); //a=a%2 </script> </body> </html>
最後來一個例子:某員工的月薪爲5000元,扣除各項保險費用共500元,我的所得稅起徵點是3500元,稅率爲3%,計算該員工的實際收入是多少。代碼以下:it
<!DOCTYPE html> <html> <head> <title></title> </head> <body> <script type="text/javascript"> var salary = 5000; var insurance = 500; var threshold = 3500; var tax = 0.03; salary-=insurance; var salary1=salary; salary1-=threshold; salary1*=tax; salary-=salary1; document.write("該員工的實際收入爲"+salary+"元"); </script> </body> </html>
運行結果爲:該員工的實際收入爲4470元