
分析:由判斷框可知應(yīng)執(zhí)行循環(huán)結(jié)構(gòu)3次即終止,據(jù)此即可求出a的值.
解答:∵0<3,由判斷框可知應(yīng)執(zhí)行循環(huán)結(jié)構(gòu):i←0+1,a←

;
∵1<3,由判斷框可知應(yīng)繼續(xù)執(zhí)行循環(huán)結(jié)構(gòu):i←1+1,a←

;
∵2<3,由判斷框可知應(yīng)繼續(xù)執(zhí)行循環(huán)結(jié)構(gòu):i←2+1,a←

;
∵3=3,由判斷框可知應(yīng)終止循環(huán)結(jié)構(gòu),并輸出a←

.
故答案為

.
點評:理解循環(huán)結(jié)構(gòu)的功能和判斷框的條件是解決問題的關(guān)鍵.